1EMOIRS OF THE CARNEGIE MUSEUM. Vol VII

SAlIME(SniE MHJSEPM IJCPEMTIIOM
TO SOUTIH ^MEESGA

SydraeV Frentice de"

.1 ; :/^

K)3. I

MEMOIRS

OF THE

CAENEGIE MUSEUM.

VOL. VII. NO. 1.

THE CHEIRODONTIN^, A SUBFAMILY OF MINUTE CHARACID
FISHES OF SOUTH AMERICA.^

By Carl H. Eigenmann.

Introductory.

The greater part of the work of preparing this monograph was done between
January and May, 1915, while enjoying the hospitahty of Mr. and Mrs. Carl G.
Fisher on their estate at Miami, Florida. President W. L. Bryan and the Trustees
of Indiana University appointed me Research Professor for the collegiate year
1914-1915, and the Director of the Carnegie Museum relieved me of resident
curatorial duties at the Museum. I thus gained the opportunity under ideal
conditions to give my undivided attention to this exceedingly difficult group of
fishes. I am indebted, as in former articles, to Dr. W. J. Holland, Director of the
Carnegie Museum, for assistance in arranging the figures in the text and on the
plates and for his editorial revision of the manuscript. The drawings given on the
plates were executed by Mr. Clarence Kennedy of Leland Stanford Jr. University.
The drawings given in the text are from camera lucida sketches made by the author.

This paper would naturally form a chapter in my Monograph of the Characidse,
to be published by the Museum of Comparative Zoology at Cambridge, Mass.,
but, as the publication of the first volume of the monograph has long been delayed,
it is deemed best to publish this article at once.

The material on which this paper is based^ consists of (a) the collections of

' Contributions from the Zoological Laboratory of Indiana University, No. 150.

' In enumerating the specimens at my disposal I have cited (a) the current numbers in the various
museums; (6) the letters a-x, indicating the number of specimens in a given series in the Carnegie Museum;
(e) the number of specimens in the particular lot under examination; (d) the size of the largest and sometimes

1

2 MEMOIRS OF THE CARNEGIE MUSEUM.

Harvard University, made chiefly by the Thayer expedition; (b) the collections of
Indiana University, made by H. von Ihering in Rio Grande do Sul, by J. D. Anisits
in Paraguay, and by Charles Wilson during the Landon-Fisher expedition to
Colombia; (c) the collections made under the joint auspices of the Indiana Uni-
versity and the Carnegie Museum on the occasion of the author's expedition to
British Guiana, and the reconnaissance undertaken by him in Colombia; and (d)
the collections made bj' INIr. John D. Haseman during the expedition of the Carnegie
Museum to central South America. The collections made by Mr. Haseman are
by far the largest both in the number of specimens and species. An account of
Haseman's travels, together with a Hst of his localities, was published in the Annals
of the Carnegie Museum, Vol. VII, p. 287. A map showing his route accompanies
the present paper.

There are twenty -one genera and fifty-six species and varieties of Cheirodontinae
now known. ^ In the present paper seven genera and seventeen species for the first
time are described. In all I have at one time or another described fourteen genera
and thirty-three species. Nineteen of the genera and thirty-nine species are repre-
sented in the collections of the Carnegie Museum. In the other museums, so far
as known, the species are represented as follows:

Paris (Mus^e National) 1

Vienna (K. K. Hofmuseum) 8

London (British Museum) 9

Genoa (Museo Civico) 2

Copenhagen (Zoologisches Museum) 1

Cambridge (Mus. Comp. Zoology) 4

New York (Am. Mus. Nat. History) 1

Washington (U. S. National Museum) 2

Pliiladelphia (Acad. Nat. Sciences) 7

Bloomington (Indiana University Museum) 35

Ithaca, N. Y. (Cornell University) 1

I have examined practically all of the known species except Cheirodon pisciculus
from western Chili and Odontostilbe pulchra from Trinidad. However, while pre-

of the smallest specimen; (e) the locality; and (/) frequently the date of collecting and name of the collector.
Where the entire series is reserved for the Carnegie Museum the letters after the current number and the
number agree. When specimens have been destroyed by dissection or otherwise, or where there are numerous
duplicates, the letters and numbers do not necessarily agree.

' I have placed the genus Psalidodon in the TetragonopterinEe, although it has the single row of notched
teeth characteristic of the Cheirodontinte. Psalidodon and Henochilus, in the latter of which there is a double
row of teeth in the upper jaw, form a little group bridging the gap between the Tetragonopterinse and Cheir-
dontinse; or, on account of the absence of lips, they may be regarded as forming a little group distinct from either
of the above. Megalamphodus ecuadorensis, sp. nov. is described in the AppencUx.

eigenmann: the cheirodontin^. 6

paring this revision, I did not have access to specimens of Aphyocharax avary
Fowler, Cheirodon eques Steindachner, Cheirodon agassizi Steindachner, Cheirodon
pulcher = nattereri Steindachner, Odontostilbe drepanon Fowler, Odontostilbe madeirce
Fowler, and Leptagoniates steindachneri Boulenger.

It is quite possible that several of these are here described under other names.
It is possible that C. agassizi is the male of Aphyocharax pulcfier, and that Odon-
tostilbe drepanon is Holesthes pequira.

The Cheirodontin^.

The subfamily Cheirodontinse (Aphyocharacinse auctorum) belongs to the large
family Characidae. All the species are small or even minute. The giants of the
subfamily are only about 90 mm. long at their best. Paragoniates alburnus reaches
a length of 90 mm. The largest recorded Grundtdus is 80 mm. long, the largest
Probolodus 81, the largest Parecbasis 80, the largest Odontostilbe microcephala 80.
Then follow Aphyocharax dentatus with a maximum length of 72 mm., Cheirodon
interruptus 60 mm., Aphyocharax alburnus and pusillus 58 mm., Holesthes pequira
56 mm., H. heterodon 50 mm., Prionobrama paraguayensis 50 mm., and P. filigerus
60 mm. The rest are aU under 50 mm. in length.

Generalized type of the subfamily. — A composite of all the known species wiU
give us an idea of the ancestor of these species, assuming for the moment that they
had a common ancestor, which is open to some doubt. However, even if a few of
the genera included do not belong to this an otherwise homogeneous group, thej'
are so nearly like them that their inclusion will scarcely impair the full value of
the generalized type.

The generalized type is a fish rather under fifty millimeters, or two inches, in
length; compressed, oval, with symmetric dorsal and ventral outlines. Its depth
at the origin of the dorsal is about one-third of the length from the tip of the snout
to the end of the median series of scales. The head is about equal to one-fourth
of this length. The eye is large, about one-third as long as the head. The mouth
is terminal and the maxillary reaches to about the origin of the eye. The cheeks
and postorbital portion of the head are protected by the well-developed chain of
suborbital bones, of which the third is in contact with the lower limb of the
preopercle, there being a naked wedge between it and the vertical hmb of the pre-
opercle. The teeth are in a single series, comparatively few in number, and with
lateral notches. Thej^ occur along the entire edge of the prcmaxillarv, at the
upper angle of the maxillary, and along the front and sides of the lower jaw. The

4 MEMOIRS OF THE CARNEGIE MUSEUM.

teeth of the maxillar}' are similar to those of the premaxillary and the lateral teeth
of the mandible are always smaller than those near the front. A frontal and a
parietal fontanel are present, the latter being the larger, truncated in front; the
former is triangular, the base of the triangle being caudad. The occipital crest is
narrowly triangular and divides the scales of the two sides for a distance of about
one-fourth of the length from its base to the dorsal. The dorsal is short, pointed,
consisting of one rudimentary and ten developed rays; having its origin midway
between the tip of the snout and the base of the middle caudal rays. The adipose
is a small free lobe as in the greater number of all the characid fishes, and is placed
over the end of the anal. The caudal is deeply forked. The anal is emarginate,
having its origin under the last dorsal raj'^, and it consists of twenty-five rays. The
ventrals are placed slightlj^ in front of the origin of the dorsal and they do not quite
reach the anal. The pectorals are lanceolate and do not ciuite reach the origin
of the ventrals. The scales are thin, verj' regularly arranged. The fins are naked
except for a few scales along the base of the anterior anal raj's. There is a well-
developed axillar}^ scale over the ventrals. There are thirty-five scales along a
median series, eight of which have lateral line pores. There is a dark spot on the
sides from about the third to the fifth scales of the lateral line, and another larger
spot on the end of the caudal peduncle and the base of the caudal. In a triangular
area over the sides of the anterior air-bladder the wall of the bodj' consists of skin
and peritoneum only.

Minor deviations from the generalized type. — The deviations from this general
type are numerous, but not very great. The greatest deviations are found in the
size of the frontal fontanel; the armature of the cheek, especiallj^ the postorbital
portion of it; the length of the anal; the degree of the development of the pseudo-
tympanum; and especially the size of the mouth and its parts and the style of the
teeth. Leaving these to be considered last, we find some of the species {Aphyo-
charax) are much less compressed than others, and in these the depth is frequently
less than one-third of the length, the minimum depth being contained about four
times in the length in a number of species of Aphyocharax. In the deepest the
depth is contained but 2.4 times in the length {Megalamphodus megalopterus) .
The head varies from 3.3-4.66 in the length in different species. It is comparatively
shortest in Paragoniates paraguayensis and comparativelj^ longest in Spintherobolus.
The eye is alwaj's large. In different species it is contained from 2.3-4.33 in the
length of the head, but in only two forms, Grundulus and Spintherobolus is it con-
tained as many as 3.75 times. In the great majority of cases it is contained 2.5-3
times. The adipose fin is absent in Grundulus and Spintherobolus, which otherwise

eigenmann: the cheirodontin^. 5

do not differ greatly from the other species. The caudal lobes may be a little
longer or shorter, a little more pointed or rounded, and there may be more or less
difference between the upper and lower lobes, but there is no striking deviation
from the type. The ventrals and pectorals may be a little longer or shorter, but
here again there is no great divergence from the central type. The scales differ
materially. The lateral line may be developed on but two scales, or it may be
complete. It is comp'ete in Probolodics, Parecbasis, Holesthes, and Odontostilbe.
It is almost complete in Microschemobrycon. In the other genera it is developed
on less than fifteen scales, the exact number varying with the species. In Gi-imdulus
the predorsal scales have disappeared; in Aphyodite the caudal has become mostly
covered with small adherent scales, and in Compsura and Odontostilbe hastata
the male s provided with a few enlarged scales on the caudal which recall the
Glandulocaudinse. The degree of the development of the pseudotympanum differs
greatly, the humeral region being apparently normal in a number of species. It
is most highly developed in Holesthes, Odontostilbe, Megalamphodus, and the deeper
species of Cheirodon. In color (alcoholic, which means the distribution of melano-
phores only) the species of this subfamily do not differ greatly from species of
Hemigrammus and HypJiessobrycon of the Tetragonopterinse. In many species
of the Tetragonopterinse and other subfamihes some sort of a spot occurs on the
sides, a little behind the origin of the lateral line. This spot is found in over half
of the species with tricuspid teeth. In the species with multicuspid teeth it occurs
only in Mixobrycon. A caudal spot at the end of the caudal peduncle and on the
base of the caudal has an even wider distribution among the Characins in general.
Among the Cheirodontinse it is all but uniformly found in the species with multi-
cuspid teeth, i. e., in those species in which the humeral spot is not developed.
Other markings are some sort of a spot on the dorsal, which occurs in six species
belonging to four genera. It is therefore not a sign of relationship. Similar spots
occur on some of the smallest Tetragonopterids. Another marking which occurs
sporadically in several species is a dark band along the tips of the short anal raj's
and across the lobe of the anal.

Deviations from the generalized type on which the genera are based. — The frontal
fontanel may be small, having the form of an equilateral triangle, and may form
only a wedge between the posterior part of the frontals (it has nearly reached the
vanishing point in Aphyocheirodon) or it may, as in Megalamphodus, be of nearly
uniform width and entirely separate the frontals.

In all but three genera, Grundulus, Spintherobolus, and Mixobrycon, the second
suborbital is in contact ^vith the p .upercle below. In both Grundidus and

6 MEMOIRS OF THE CARNEGIE MUSEUM.

Spintherobohis the suborbitals are feeble, very different from those in the other
genera. In Mi.robrycon there is a naked area around the entire distal edge of the
third suborbital, similar to that in most of the Tctragonopterinse. The greatest
difference in the armature of the cheeks occurs in the postorbital region. In
Aphyocharax there are two postorbitals. Of these the ui)per is minute and neglig-
ible, the lower is large, convex, similar to the third suborbital, and covers the entire
postorbital area. Prionobrama has a similar arrangement. In other genera there
are three or more postorbitals and there is a wider or narrower naked area between
them and the vertical limb of the preopercle. In one genus, Aphyocheirodon,
there is considerable individual variation in the number and size of the postorbitals.
Anal fin. — The anal varies. In Cheirodon anna the base is very short, entirely
behind the dorsal, the margin is rounded, and the highest rays extend beyond the
tip of the last. In Paragoniates, Leptagoniates, and Phanagoniates the base is very
long, having its origin below the first dorsal ray or far in front of it. In Prionobrama
its margin is extremelj^ falcate. Between these extremes there are various modi-
fications, the rays varying from twelve in Spintherobolus, fourteen in Leptobrycon,
Cheirodon anna\ and Cheirodon piscicidns, to fifty in Paragoniates alburnus, and
seventy in Leptagoniates. In the great majoritj' of species the number of rays
ranges between twenty and twenty-six. In the genus Cheirodon, the species of
which fall into two groups, the greatest range is from twelve to twenty-seven.
In C. piscindvs and C. aimer the number of raj^s ranges from twelve to fifteen;
and in the nine other species from seventeen to twenty-seven. In seventy-nine
specimens of one species, Cheirodon interruptus, the number of anal rays is as follows:

Number of rays: 17, 18, 19, 20, 21, 22, 23, 24

Number of individuals: 2 6 2S 16 12 11 3 1

These are from several distinct localities, and the extremes have not been
observed in specimens from one locality.

Dorsal fin. — The variation of the dorsal is not nearly as great as that of the
anal, and therefore of less taxonomic importance. Usually its origin is a little
behind or in front of the middle of the body, the distance in either direction being
negligible, but in Grundulus and in Prionobrama, Paragoniates, Leptagoniates, and
Phanagoniates it is distinctly behind the middle. Its outline may be rounded, ob-
liquely truncate, or it may be distinctlj^ falcate as in Parecbasis. It reaches its
extreme development in Megalamphodus megalopterus.

Mouth. — The greatest evolution in this group, as in the rest of the Characins,
has taken place in the mouth and teeth. The mouth ranges in size from such a
minute affair as is found in Oligobrycon microsiomus, Compsura heterura, Cheirodon

EIGENMANN: the CHEIRODONTINiE. 7

notomelas, and C. piaba, to the clupeoid openings in Leptobrycon jatuarance, Macro-
psobrycon uruguayance, Megalamphodus megalopterus, and M. micropterus. But the
size of the mouth in itself is of no great importance, for there is great variation
within such genera as Aphyocharax and Chcirodon. There is very great difference
in the size and shape of the prcmaxillary and maxillary, as the outlines in the
text-figures show.

Teeth. — The greatest interest centers in the teeth. In Grundulus aU of the
teeth are peg-like, conical, single-pointed. Such teeth frequently appear on the
sides of the lower jaw, when the teeth are otherwise very different. They are also
frequently found on the distal part of the maxillary, when the number of teeth on
this bone are considerable, and they are also found in the premaxillary when the
teeth are feeble or numerous. The next degree of complexity is found in the three-
pointed teeth in the genera Spintherobolus, Probolodus, Aphyocharax, Macropso-
brycon, Microschemobrycon, and Oligobrycon. In Aphyocheirodon there are three-
to five-pointed teeth in the upper jaw and five-pointed teeth in the lower jaw. In
the remaining genera the teeth have typically five or more points. Frequently
the teeth in the sides of the lower jaw are not only smaller, but belong to a lower
order, i. e., they have fewer points than the others in the same mouth. The same
may be true, but to a less extent, of the teeth on the outer part of the premaxillarj-
and on the distal part of the maxillary. Usually the number of teeth in any bone
differs inversely as the number of points to each tooth, though this is not always the
case. In the species with many-pointed teeth the number of teeth is usuallj' very
limited, none to three in the maxillary of Cheirodon, none to four in Odontostilbe,
but in one species of that genus ranging from four to seven. However, several of
the genera with tricuspid teeth have no teeth on the maxillary, others have as
many as twenty or more.

To say that the teeth are unicuspid, tricuspid, or multicuspid, does not tell
the whole story. There have evidently been divergent radiations within each of
these groups both in the shape of the individual teeth and in their arrangement.
These teeth are so difficult to observe, even with the aid of the modern binocular
microscope and a spot-light, that in all cases where I had material the individual
bones were dissected out and mounted in balsam. Camera-lucida sketches were
then made. Under all the circumstances I think it will be best to entirely ignore
statements about the teeth in the older descriptions, whether made by myself or
by others. Statements that the entire edge of the maxillary is denticulate and
that there are no teeth in the maxillary are especially to be doubted.

Reverting to the modifications of the three types of teeth, unicuspid, tricuspid,

8 MEMOIRS OF THE CARNEGIE MUSEUM.

and multicuspid, it maj' be observed that the conic tooth may be a simple cone, but
is much more likely to be recurved. All the teeth of Grundulus are of this type.
Part of the teeth on the maxillaries of the genera with tricuspid teeth are also uni-
cuspid, and probably by degeneration some of those on the premaxillary. The
tricuspid tj^^e varies from a slender conic tooth with a minute notch on each side
to a tooth in which the three points are of about equal size, nearly coterminous, and
arranged in a line, to a heavy tooth with a blunt central point and two minute
lateral points, so arranged that the three points mark the angles of a triangle
(Proholodus) . The five- to nine-pointed teeth may have a large central cusp and
two graduate cusps on the sides of the tooth, the line connecting the five (or more
points) forming parts of an ellipse, or the points may be of nearly equal value and
nearly coterminous. Between these there are many shades, several variations
not infequently occurring in different parts of the same jaw. A very distinct tj^je
of tooth as well as arrangement is found in the lower jaw of Aphyocheirodon. The
teeth in this jaw are usually five-pointed. The three middle points are of about
equal size and subtruncate, so that their tips form chisels rather than points.
The outer cusps are verj^ minute and so far withdrawal from the level of the rest
that they are easily overlooked. That this surprising shape is not the result of
wear is shown by the relaj'-teeth which have the same shape as the rest. With all
these modifications the sides of the multicuspid teeth may be parallel or very
much contracted basally. The teeth are usually quite flat, or rather thin, but in
Mixobrycon the teeth are heavj^ and approach the shape of the teeth of the Tetra-
gonopterinffi. In all but one species the teeth are strictly uniserial. In Megalam-
phodus micropterus one of the teeth of the premaxillary is sometimes out of line
with the rest, a little further forward, and forms either an incipient or a reminiscent
anterior series.

The number of teeth as well as the shape of the teeth described above indicate
that the dentition of this group of the Characins is highly specialized. In this
character of high specialization they are not unique among the Characins, for it is
in the shape, number, and arrangement of the teeth that the greatest divergence
has taken place. '

The number of teeth on the premaxillarj- and the frequencj' of the appear-
ance of any given number is indicated in the following table:

Number of teeth in premaxillary: S, 4, 5, 6, 7, 8, 9, 10, 11, IS, IS, 14

Numberof species having the given number of teeth: 171110 14 96 5 2 2 1 2

In this table seventeen species occm- in more than one count; to be exact, five
species occur in two counts, ten in three, one in four, and one in five. In other

eigbnmann: the cheirodontin.e.

words, in five species there may be a deviation of one tooth from the normal, in ten
species there may be a deviation of as many as three teeth (Aphyocharax seven to
ten), and in one {Odontostilbe melandeta) there may be a deviation of as many as

CC3

Fig. 1. Types of teeth and their variations in the Cheirodontina;. a, mandibular tooth of Gruudulus;
& and 6', premaxillary teeth of Macropsobrycon; c-c^, premaxillary teeth of Aphyocharax anisilsi, c, the sym-
physeal tooth, c\ the second, and c^ the third tooth from it; d, mandibular tooth of Megalamphodus megalop-
terus; e, mandibular tooth of Spinthcrobolus; f and/', a mandibular and premaxillary tooth of Parecbasis; g
and g^, a maxillary and premaxillary tooth of Prionobrama; h-K , entire set of mandibular teeth of au Oligo-
brycon microstomus; i-i', entire set of premaxillary teeth of a ^[cgalamph(>dus microptcnis, i and i', the usual
type, i^ with inciiiient cusps on the sides of the median cusp; j-/, entire set of premaxillary teeth of an Aphyo-
chcirodon; f and/, active mandibular teeth of an Aphyocheirodon; j'", relay tootli, which has not pierced the
gum of an Aphyocheirodon; k, fc', k-, fc', a mandibular tooth, a prcmaxillaiy tooth, and two maxillary teeth of
Compsoura helerura; W, a premaxillary and a maxillary tooth of a Chcirodon piaba.

10 MEMOIRS OF THE CARNEGIE MUSEUM.

four teeth. But of this latter species I have but few specimens, unsatisfactorily
preserved, and the result is doubtful. The larger number of the species have seven
premaxillary teeth. The number of species having six or eight teeth are nearly
equally matched. It must be borne in mind that the number of specimens examined
has not been so great that we can be sure that all variations have been observed.
The maxillary teeth recorded are as follows:

Number of teeth: 0,1, 2, 3 , 4, 5, 6, 7, 8, 9, 10, 11, 1:2, 13, 14, 15, 16, 17, 18, 19, 20
Number of species: 47 19 10 7552113 2 4 4 3 2 2 1 1 1 3

Four of the species occur in two counts, six occur in three, four in four, one in
five, one in seven, and one in twelve (from nine to twenty in Aphyocharax dentatus).
The prevailing number is two teeth, which are found in nineteen species, as shown
by the table; which also shows that the number of species having from twelve to
fourteen and twenty teeth is relatively greater than those having from seven to
eleven, and from fifteen to nineteen teeth.

The Relationship of the Cheirodontin^.

Are the Cheirodontinie a homogeneous group with a common ancestry, or
are they dwarfs of various other subfamilies? The most of them form a homo-
geneous group, divisible, however, into a number of minor groups. Doubt arises
as to Grundulus, which has only conic teeth, Paragoniates, Leptagoniates, and
Phanagoniates with a posterior dorsal, and Mixobrycon, which has tetragonopterid
teeth and cheeks. Certain other characters, notably the peculiar scaling in the
caudal of the males of Compsura and Odotitostilbe hastata, also suggest relationship
to another subfamily, the Glandulocaudinse.

The unicuspid teeth of Grundulus suggest relationship with the Characinse,
as some of the Characinae with partially tricuspid teeth, Oligosargus exodon, and
Bramocharax suggest relationship with the Cheirodontinse. The general shape and
backward position of the dorsal of Paragoniates as well as the peculiar scales in the
tail of the male Compsura and Odontostilbe recall the Glandulocaudinse. The
heavy teeth and armature of the cheeks of Mixobrycon suggest Hyphessobryco7i of
the Tetragonopterinse and so does the tooth out of line with the rest in Megalam-
phodus micropterus. However, a double row of teeth has several times been evolved
in the Characinae from a single row; or a single row from a double row. I have
pointed out such cases in Indiaua University Studies No. 20, and will have occasion
to point out others in the monographs on the Chalcininge and Gasteropelicinse.
In fact if it were not for other considerations, the single series of teeth in the Cheiro-
dontinse would be no more sufficient to segregate them from the Tetragonopterinse

EIGENMANN: the CHEIRODONTINiE. 11

than would the completeness or incompleteness of the lateral line justify the col-
location of the genera having these characters in subfamilies.

In the peculiar armature of the cheeks Prionobrama shows such similarity to
Aphyocharax that Cope placed it in the latter genus. In spite of its general appear-
ance and the backward position of the dorsal, Prionobrama is probably more nearly
related to Aphyocharax than to any member of the Glandulocaudinse.

The peculiar scaling of the caudal in two of the species recalls the similar
character in the Glandulocaudinse and in Argopleura of the Tetragonopterinae.
It is possible that this is also an independently acquired character in a number of
remotely related genera.

While it is very probable that we are dealing with a natural group, it is certain
that different members point to three distinct subfamilies from which they may
have been derived, or to which they may have given rise. The Cheirodontinae
are certainly near the generalized type of all the Characins.

Secondary Sexual Differences.

There are no conspicuous secondary sexual differences in the group under con-
sideration, unless there should be a striking difference in the hpochromes, which
have been dissolved in alcohol.

The differences when present consist in the length of the fin-rays, in the fila-
mentous termination of the fins, in the development of hooks on the anal, and less
frequently on the caudals and ventrals of the male, in the development of scaly
pockets on the caudal of the males, in the color of the dorsal, and, what is unique
for this group, in the high development of the interhsemals in the male in Cheirodon.
The details are given under the respective species.

Distribution.

The Cheirodontinae apparently reach their maximum development in the
middle Amazon and the upper La Plata basins. It is quite possible that this
greater abundance in the middle Amazon and in the Paraguay basin is apparent
rather than real. Little collecting has been done with fine meshed nets in the
Orinoco and in the upper waters of the Amazon.

The group as a whole has a very wnde distribution. The genus Cheirodoti has
a range all but coextensive with that of the subfamily. The species, with the
exception of Cheirodon piaba Llitken, are confined to rather limited ranges. Only
two species are found both in the Paraguay and in the Rio Guapore. A number of
species in the Madeira and Paraguay are evidently very closely related.

12

MEMOIRS OF THE CARNEGIE MUSEUM.
Table of the Distribution of the Species of the Cheirodontin^.

1

<s
U

l.s"

<

a

'a
O

.a

i

i

'3
•c

a

■c

o

g

•s

■a

1

1
A

1

IK

o
■a

-a

i

o
t4

a'i

.OJ
« o

II

(CO

is

u

2
S

s

■ft

1

•a g

-rt a

V

u

'3 °

s

X

6
s

1

1

1. Grundulus bogotensis (Humboldt)

2. Spinlherobolus papillifertis Eigenmaiin

X

3. Probolodus kelerostomus Eigenniann

X

4. Aphyocharax dentatus Eigenmann & Kennedy. . .

X

.

5. Aphyocharax alburmis (Giinther)

X

X

6. Aphyocharax erylhrurus Eigenmann j . . .

X

X

X

8. Aphyocharax anisilsi Eigenmann & Kennedy. . . i

X

X

9. Aphyocharax avary Fowler

X

X
X

?

11. Aphyocharax paraguayensis Eigenmann i. . .

12. Aphyocharax nallereri (Steindachner)

X
X

f

13. Aphyocharax agassizi (Steindaclmer)

14. Aphyocharax maxillaris Ulrey

. . .1. . .

1.5. Paragoniates alhurnus Steindachner

X

16. Prionobrama paraguayensis (Eigenmann)

X

17. Prionobrama filigerus (Cope)

X
X

X

18. Lcptagoniates steindachneri Boulenger

19. Phanagoniates wilsoni Eigenmann

X

X
X

X

21. Leplobrycon jatuaranw Eigenmann

22. A phyodite gramviica Eigenmann

X

23. Macropsobrycon uruguayance Eigenmann

X

24. Megalamphodus megalopterus Eigenmann

X

25. Megalamphodus eques (Steindachner)

X

26. M cgalamphodus melanotus Eigenmann

X

X

28. Megalamphodus micropterus Eigenmann

X

29. Microschemobrycon guaporensis Eigenmann

X

30. Oligobrycon microstomus Eigenmann

X

X

32. Compsura heterura Eigenmann

X

X

33. Mixobrycon ribeiroi (Eigenmann)

X

34. Cheirodon pisciculus Girard

Y

35. Cheirodon annw McAtee.^

36. Cheirodon insignis Steindachner

X

37. Cheirodon parahybce Eigenmann

X

38. Cheirodon intemiptus (Jenjais)

X

39. Cheirodon monodon Cope

X

40. Cheirodon ibicuhyensis Eigenmann

X

X

42. Cheirodon madeirm Eigenmann _

X
X

43. Cheirodon piaba Liitken

X
X

X

X

X

45. Cheirodon stenodon Eigenmann

X

46. Holesthes pequira (Natterer)

X

X

X

X

X

X

48. Odontostilbe hastata Eigenmann

X

49. Odmitoslilbe drepanon Fowler. . .

X
X

X

X

X

52. Odonioslilbe pulchra (Gill)

X

X

54. Odontostilbe madeira Fowler. .

X

55. Odontostilbe melandeta Eigenmann

X

3

4

1

13il2

13

6

5

2

4

4

2

1

1

' Habitat unknown. For Megalamphodus ecuadorensis sp. nov. Cf. Appendix.

eigenmann: the cheirodontin^.

13

The paired species are as follows :

Rio Madeira and its tributaries

Aphyodmrax alburnus
Aphyodmrax pusillus
Prionobrama filigerus

Rio Paraguay

Aphyocharax dentatus
Aphyocharax anisitsi
Prionobrama paraguayensis

Cheirodon pisciculus, which ranges in western Chile at least from Santiago to
Puerto Montt, is one of two species of this group found on the Pacific slope. This
species also has the distinction of being the only member of the family of Characins

tJrJtihlh".

Fig. 2. Phylogenic arrangement of the genera of the Cheirodontinae. In tliis diagram the letters cor-
respond to and have the significance of the same letters in the following key. The genus Paragoniates, in
the diagram, includes the genus Prionobrama, now recognized as distinct.

14 MEMOIRS OF THE CARNEGIE MUSEUM.

which is found on the Pacific slope south of the dry area of central South America.
Members of the genera Cheirodon and Odontostilbe are found in the Chagres and
Atrato rivers in Panama and Colombia. Megalamphodus ecuadorensis is known
from one specimen taken in western Ecuador.

The highest altitude is reached by Grundidus, which swarms in the streams of
the plains of Bogota at an elevation of about 9,000 feet. Several species are
found in the San Francisco basin at a considerable elevation. The rest are, as
far as knowTi, confined to the low lands.

Phylum PISCES Artedi.

Class TELEOSTOMI Bonaparte.

SuPERORDER OSTARIOPHYSI Sagemehl.

Order PLECTOSPONDYLI Cope.

Suborder HETEROGNATHI Cope.

Family CHARACID^ Gill.

Subfamily Cheirodontin^ Eigenmann.
Teeth well-developed, in a single series, arranged vertically in the premaxillary,
dcntary, and usually the maxillary. Usually some of the teeth with one or more
notches or cusps symmetrically arranged on either side of the median cusp. Ventral
surface rounded or slightly compressed, without serrations; bodj' scaled; a parietal
and a frontal fontanel; dorsal short, with eleven or fewer raj^s; gill-membranes
free from the isthmus and from each other; nares close together, separated by a
flap only; adipose fin usually present.

Key to the Genera of the Cheirodontix.e.
a. No adipose fin; mouth small; armature of cheeks very weak. Teeth conic or triscupid in both jaws; lateral
line incomplete.
6. Predorsal area partly naked; tactile papiUse normal; teeth all conic in a regular series.

1. Grundulus ^^alenciennes.
66. Predorsal area entirely scaled; tactile papillte excessively developed; teeth mostly tricuspid or conical.

2. Spintherobolus Eigenmann.
aa. Adipose fin weU developed, except in No. 7, Phanagoniales, which see.
c. Teeth tricuspid or conic.

d. Teeth few, very heavy, tricuspid, five or six in each dentary, of which the first is directed upward
and outward, the third laterad, the fourth and later ones upward, at nearly a right angle to the

eigenmann: the cheirodontiNjE . 15

third; premaxillary with three or four teeth directed downward and forward, maxillary with
three to five similar teeth; third suborbital covering entire cheek in adult; three postorbitals
with only a very narrow naked border; scales small, 45-53; lateral line complete; anal long;

interha;mals normal 3. Probolodus Eigenmann.

dd. Teeth slender, tricuspid, or conical in both jaws. Intcrhxmals normal.'

e. Third suborbital covering the entire cheek, two postorbitals, of wliich the upper is minute,
' the lower very large, similar to the third suborbital, and covering the entire area from
eye to pre-opercle; lateral line incomplete. Anal with seventeen to twenty-seven rays
in "/" and twenty-nine to nearly forty in "ff."

f. Anal short, with a blunt lobe or none; origin of anal behind the vertical from the middle

of dorsal; mouth variable, maxillary with from two to twenty teeth; dorsal and ventral
profiles similar in front of the vertical from the dorsal; caudal naked.

4. Aphyocharax Giinther.

ff. Anal long, the anterior rays long, filiform; origin of anal about on the vertical from

the origin of the dorsal; mouth large, maxillary with teeth along its entire margin

directed downward and backward, largest near the middle; ventral profde much more

arched than the dorsal 5. Prionobrama Fowler.

ee. Third suborbital large, the fourth in one genus at least smaller than the fifth or second post-
orbital. Anal with more than forty rays, its origin in advance of that of the dorsal.
x^. Adipose dorsal small; lateral line incomplete; anal not falcate; teeth along entire
maxillary; origin of dorsal but little behind vertical from origin of anal, which is

equidistant from snout and base of middle caudal rays.

6. Paragoniates Steindachner.

xx^. Adipose dorsal small; lateral line complete; origin of anal equidistant from snout and

the fourth fifth of its base 7. Leptagoniates Boulenger.

xxx^. No adipose; lateral line short; origin of anal equidistant from the snout and the pos-
terior fourth of its base S. Phanagoniates Eigenmann & Wilson.

eee. Third suborbital variable; three postorbitals, of which the uppermost is minute; all of them
sometimes feeble. Anal moderate, its origin bcliind that of the dorsal.

g. Teeth minute, very slender, many conical, except in No. 17.

h. Lateral line complete; caudal lobes partly scaled; no pseudotympanum; tliird sub-
orbital covering entire cheek; postorbitals large, but feeble; maxillary without
teeth, its upper margin thickened; sides of lower jaw raised, without teeth; origin

of dorsal in front of the middle 9. Parecbasis Eigenmann.

hh. Lateral line incomplete.

i. Anal short, of fourteen rays, the liighest extending beyond the tip of the last, its
base equal to length of caudal peduncle; no teeth on the sides of the lower jaw,
or on the maxillarj^; sides of the lower jaw liigh, as in Parecbasis; maxillary
large, its outer margin very convex; lateral line very short.

10. Leptobrycon Eigenmann.

u. Anal long, twenty-three to thirty rays, the highest ray not extending to the base

of the last ray.

* Dorsal 9-11, Chcirodontina;; the Crenucliina;, which arc similar to the foregoing, have dorsal 15-18.

'The letters x, xx and xxx are used here out of order because text-figure 2, in which the letters were

made to agree with those in the key, was drawn before genera 6 to 8, which are quite aberrant, were

included in this monograph.

16 MEMOIRS OF THE CARNEGIE MUSEUM.

j. Lateral line with but few pores; cheeks behind the eye mostly naked.

k. Caudal partly scaled 11. Aphyodite' Eigenmann.

kk. Caudal naked.

I. PseudotjTnpaniun conspicuous; no teeth on maxillary; interorbital
very conve.x; frontal fontanel moderate; premaxiUarj' with five,
to seven mostlj' conical teeth, similar to Parecbasis; the lateral

line incomplete 12. Macroiobrycon Eigenmann. C'^'^' ''A

U. No pseudotjTnpanum; majdllary with two to twenty teeth; four
to eight tricu.spid teeth in front part of mandible, minute teeth on
side; fontanels very large.. . .13. Megalamphodus Eigenmann.
jj. Lateral line extending to within fom' scales of the caudal. Twentj'-five
or more teeth on each ramus of the mandible; twelve teeth on the maxil-
lary; frontal fontanel moderate; cheeks behind as well as below the eye
covered; mouth moderate; subfusiform.

14. Microschemobrycon Eigenmann.
gg. Teeth heavy, four on the premaxillary; mouth minute; maxillary not reaching to below
eye, with one or two teeth; origin of dorsal equidistant from snout and caudal; no
pseudotympanmn; three postorbitals covering nearly the entire postorbital area.

15. Oligobrycon Eigenmann.
cc. Teeth in part at least with five or more lobes.

m. Sides of teeth nearly parallel, those of the upper jaw narrow, with a prominent median cusp and
one or two minute cusps on each side, about ten teeth in each premaxiUary; mandible with
three- to five-lobed teeth, much expanded at tip, the three middle lobes equal in size, blunt,
those of successive teeth in contact, forming a continuous cutting edge, the lateral lobes
excessively minute; mouth large, cheeks partly naked; frontal fontanel very short; no pseudo-
tympanum; interhaemals normal ; lateral fine incomplete. .. 16. Aphyocheirodon Eigenmann.
mm. Teeth with five or more points, tops of those of the lower jaw not forming a continuous cutting
edge.
n. Lateral line incomplete.

0. Male with a lobe of large scales exi ending along the base of the middle caudal rays; all
but three or four last anal rays of the male ■ftith hooks; interhaemals of the caudal
peduncle weak; mouth minute; maxillary barely reaching to below ej'e; second sub-
orbital covering the entire cheek; postorbitals verj' weak; no pseudotympanum;

frontal fontanel moderate 17. Compsura Eigenmaim.

00. Caudal of male without a median lobe of scales.

p. Interhaemals of the caudal peduncle of the male, next the caudal, feeble; no pseudo-
tympanum; teeth heavy, one on the maxillary; third suborbital with a naked

border 18. Mixobrycon Eigenmann.

pp. Interhaemals of the caudal peduncle, especially in the male, prominent, spine-like,
protruding; a conspicuous pseudotjTnpanum; one to three teeth on the maxillary;
teeth of upper and lower jaw similar, with five or more points.

19. Cheirodon Girard.
nn. Lateral fine complete; interhaemals feeble, not projecting; maxillarj' with a few broad-tipped
teeth; second suborbital in contact ■^vith the preopercle below.
^ Aphyodite, Macropsohrycon, and some of the species of Megalamphodus are very similar.

eigenmann: the cheirodontin^e. 17

q. Premaxillary teeth but little expanded toward the tips, pointed, tiie median point a little
the larger; mandihulury teeth mucli expanded at the tip, wth a small basal notch on
each side and three median points of about the same size; third suborbital in contact

with the prcopercle below; fontanel short 20. Holesthes Eigenmann.

qq. Teeth of the upper and lower jaws similar; maxillary with a few broad-tipped teeth;
third suborbital in contact with the preopercle below. Caudal in the male naked or
with a row of scales reaching to the tip of the rays just below the shortest ones at the
^'^'^''^ 21. OdontostUbe Cope.

Genus Grundulus^ Valenciennes.
Grundulus Valenciennes, Hist. Nat. Poiss., Vol. XVIII, 1846, p. 216.
Ctenocharax Regan, Ann. & Mag. Nat. Hist. (7), Vol. XX, 1907, p. 402.

Type: Poecilia hogotensis Humboldt.

Cyprinodontoid fishes, reaching a length of about 80 mm., found on the
eastern highlands of Colombia.

Teeth all recurved, conical, in a single series on greater part of maxillary, on
premaxillary and mandible; third suborbital in the largest specimens a little wider
than the naked area around its convex border, narrower than the naked area in
the young; postorbital area naked; mouth small, maxillary just about reaching
the orbit; eye comparatively small, placed high; a wide naked strip from dorsal
to head, and another along middle of belly; dorsal placed behind the middle; origin
of ventrals near the middle; anal short; no adipose fin; pectorals not nearly
reaching ventrals; lateral fine short; scales with very many faint, diverging radial
striae; no pseudotympanum. Gill-rakers about 8 + 10, very short, about one-third
as long as eye; a few feeble interhaemals appearing as caudal fulcra; a larger num-
ber of interneurals, but equally feeble.

1. Grundulus bogotensis (Humboldt). (Plate II, fig. 1.)
Native name "G'Mopuc/ie."
Pcecilia bogotensis Humboldt, Recherches sur les Poissons Fluviatiles, in Rec.
d'Observations, Zoologic et Anat. Comp., Vol. II, 1821, pp. 154 and 159
pi. XLV, fig. 1.
Ctenocharax bogotensis Regan, Ann. and Mag. Nat. Hist. (7), Vol. XX, 1907, p.
403 (Bogota).

Range: The rivers of the plains of Bogota and northward in the streams of
Santander.

5084, C'. M., 12843, I. U. M., over one thousand specimens, largest 80 mm.
North of Bogotd at Puente do Suba. Eigenmann.

' Probably from Grundules, an appellation of the Lares.

18

MEMOIRS OF THE CARNEGIE MUSEUM.

5085, C. M., 12844, I. U. M., eighty. Esperanza. Eigenmann.

5086, C. M., 12845, I. U. M., two. Electric light plant at edge of plains of
Bogota. Eigenmann.

5087, C. M., 12856, I. U. M., one hundred and fifty. Madrid. Eigenmann.

5491, C. M., 13182, 1. U. M., nine, largest 70 mm. Boyaca, Rio Chiquinquiseto.
Gonzales.

5492, C. M., 13183, 1. U. M., three. Quebrada Zuaita, Santandcr. Gonzales.
Head 3.5-3.7; depth 3-3.3; D. 11, rarely 10; A. 13-16; scales in a median

series 32-34 of which 4 to 6 bear pores; eye 4-4.45 in the head, equal or nearly equal

Fig. 3. Grundulus bogotensis (Humboldt), a, maxillary; 6, premaxillary; c, mandible.

to the snout, 1-1.33 in the interorbital. Compressed but heavy, dorsal and ventral
outlines equally curved; the head rather blunt. Preventral area rounded, naked
in the middle below the pectorals, the scales bordering the naked area rounded,
isolated from each other; area along base of dorsal narrowly naked, a naked
area in front of the dorsal as wide as the eye, growing wider toward the head and
extending on both sides of the occipital process; the scales bordering the area sub-
circular, small, isolated from each other; occipital process reaching about one
seventh to the dorsal; interorbital broad; frontal fontanel large, entirely separating
the frontals in the young, in contact for a variable length in the adult, frontal
fontanel being nearly as long or only half as long as the parietal. Mouth moderate,

eigenmann: the cheirodontin^. 19

the maxillary oblique, about equal to length of eye; seven to nine teeth in the pre-
maxillary, nine or ten teeth in the maxillary, about thirteen to sixteen teeth on
the dentary; tooth-bearing portion of dentary over half the length of the lower jaw.

Origin of dorsal about equidistant from preopercle and base of middle caudal
raj's; margin of dorsal rounded, the fifth ray highest, little if any longer than post-
orbital portion of head; caudal but feebly forked, its lobes short, about equal to
length of head less snout; origin of anal under posterior part of dorsal; base of
anal half as long as head, or a little 'onger; margin of anal nearly straight or
rounded in front, without lobe, the fifth ray highest; ventrals nearh' reaching
anal, or a little beyond the base of the first ray; pectorals broad, reaching half-way
to middle of ventrals; origin of ventrals in middle, or a little behind the middle of
the distance from snout to caudal.

Scales of middle of s'des large, decreasing rapidly towards the back and belly.
No scales on base of anal or caudal.

Sides reticulated with dark, basal angles of scales very dark; upper parts of
head and naked predorsal area blackish, an obscure humeral spot over and some-
times on the second and third scales of the lateral hne; no caudal spot, a faint dusky

lateral band.

Genus II. Spintherobolus Eigenmann.*

Spintherobolus Eigenmann, Ann. Carnegie Mus., Vol. VIII, 1911, p. 167, PI. V,
figs. 1-4.

Type: Spintherobolus papilliferus Eigenmann.

Teeth tricuspid, in a single series in dentary, premaxillary, and upper part of
maxillary; no adipose fin; lateral line on one or two scales; caudal naked; anal
very short, naked; tactile papillae excessively developed; suborbitals very feeble;
predorsal area fully scaled.

2. Spintherobolus papilliferus Eigenmann. (Plate III, figs. 1-4.)
Spintherobolus papilliferus Eigenmann, I. c.
Range : Upper Ticte basin.
3882, C. M., type 41 mm. 3883, C. AL, paratypes, four. 25-39 mm. Alto

da Serra, Tiet^ basin, Sao Paulo, Aug. 4, 1908. Haseman.
Head 3.33; depth 3; D. 11; A. 12; scales 35, 13 between dorsal and ventral;
eye 4.3; interorbital 3.5 in the head.

Cyprinodontiform; profile sloping rapidly to above the ventrals; caudal
peduncle a trifle less than half the greatest depth, length of the peduncle twice its

« <Twti^ripo06\oi, emitting sparks, referring to the appearance of the yellow tactile organs of the head.

20

MEMOIRS OF THE CARNEGIE MUSEUM.

height; predorsal area with thirteen scales, preventral area short, rounded, without
a distinct median series of scales; occipital i^rocess aliout six times in the distance
from its base to the dorsal; frontal fontanel a very nar-
row slit; cheeks entirely naked; the suborbitals verj'
narrow, concealed; mouth small, terminal; about six
arrow-shaped teeth on the maxillary; seven similar
more distinctly three-lobed teeth on the preniaxillary;
eight similar and two conical teeth in each dentary;
organs of lateral line excessively developed about the
head, each papilla orange; no gill-rakers.

Origin of dorsal near middle of body, its highest ray
four and one-half times in the length; caudal lobes four
to four and one-half times in the length; anal very
short, its origin equidistant from preopercle and caudal;
ventrals reaching to the anal, as long as the base of the
latter; pectorals reaching beyond the origin of the ven-
trals. Pores of lateral line on only two scales. Scales regularly imbricate, no inter-
polated rows; caudal and anal naked; axillary scale minute.

Scales of sides outlined in dark, a dusky spot over the scales with developed
pores.

This species, which resembles Grundulus in many ways, is known to occur only
in small rills leading into the Rio Tiete and thence into the Parana, at Alto da Serra
near the coast at Santos, Sao Paulo, Brazil. The related genera Grundulus and
Spintherobolus are thus known from nearly opposite parts of South America.

Fig. 4. Spintherobolus papil-
ii/erus'Eigenmann. a, premaxil-
larj'; b, maxillary; c, mandible.

Genus III. Probolodus^ Eigenmann.
Probolodus Eigenmann, Ann. Carnegie ]\Ius., Vol. VIII, 1911, p. 164, fig. 1; PI.
IV, fig. 1.

Type:. Probolodus heterostomus Eigenmann.

Premaxillary with three teeth somewhat directed outward, each with three
points in the angles of a nearly isosceles triangle, the middle point, which is also
the anterior one, much heavier; maxillary with three to five teeth, the first two or
three of which are directed outward; each ramus of the mandible with four larger
teeth, the first three directed outward, the fourth and one or more smaller ones
following it, directed upward; the larger teeth of the lower jaw heavy, conical,
with a minute cusp on each side. Lateral line complete; caudal naked. Adipose

' Trpo0o\ri = a putting forward; 65oi.s = a tooth.

EIGENMANN: the CHEIRODONTINiE. 21

well-developed. Mouth large; lower jaw heavy, its sides vertical; third suborbital
in contact with preoperclc below and behind in the larger, with a narrow naked
border in the smaller specimens; three postorbitals covering the entire postorbital
area; no pseudotympanum; frontal fontanel very long; the frontals not in contact.

3. Probolodus heterostomus Eigenmann.
Probolodus heterostomus Eigenmann, Ann. Carnegie Mus., Vol. VIII, 1911, p. 164,

fig. 1 ; PI. IV, fig. 1. (Campos on the Rio Parahyba; Iporanga on the Ribeira.)

Range: Southeastern Brazil in coastal streams from the Rio Doce to the
Ribeira da Iguap^.

2973, C. M., type, 63 mm. ; 2974, C. M., paratypes, three, 48-64 mm. Campos
on the Parahyba. June 13, 1908. Hascman.

2975, C. M., paratypes, two, 78-81 mm. Iporanga on the Ribeira, Dec. 1, 1908.
Haseman.

20910, M. C. Z., one, 77 mm. Rio Doce, between Ijinhares and Porto Souza,
Hartt and Copeland. Thayer Expedition.

6882a, C. M., 45 mm. Sao Joao do Barra, Rio Parahyba. Haseman.

6879a-b, C. M., two, 37 and 44 mm. Jacarehy, Rio Parahyba, July 15, 1908.
Haseman.

6880a-g, C. M., seven, largest 35 mm. Jacarehy, July 4, 1908. Haseman.

Head 4-4.33; depth 2.66; D. 11; A 26-31; scales 8 or 9^5 to 53-7 to ven-
trals; eye 3, interorbital 2.5, snout 3.5 in the head in the tj'pe, 2.5, 3.2, 3.5 respec-
tively in the paratypes.

Dorsal and ventral outlines nearly equally curved, without distinct humps or
depressions; ventral region rounded, the postventral area narrowlj^ so. No regular
series of median scales in front of the ventrals. Predorsal area narrowly rounded,
with a regular median series of about twelve scales. Occipital process about five
times in the distance from its base to the dorsal, bordered by four or five scales
on each side; interorbital rounded, the frontal fontanel little more than half as
long as the parietal without the occipital groove. Snout sharp, the lower jaw
entering the profile when the mouth is closed; a distinct angle between maxillary
and premaxillary ; maxillary not quite equal to length of eye; third suborbital
leaving a naked border around its entire lower edge. (^»ill-rakers 6 -|- 12.

Scales everywhere regularly imbricate, exc(>ptover the anal musculature; caudal
naked, a weak anal sheath of one series of scales along (he bas(> of the anterior rays;
each scale of the side, with several (maximum about eight) radial strite; axillary
scale of the ventrals well -developed.

22

MEMOIRS OF THE CARNEGIE MUSEUM.

Dorsal small, about four times in the length; adipose well -developed; caudal
forked, the lobes three and one-half to four times in the length; anal slightly
emarginate, the highest ray reaching tip of thirteenth ray. Ventrals not quite
reaching anal, pectorals to, or a little beyond, origin of ventrals.

Fig. 5. Probolodus heteroslomus Eigenmann. a, outlines of side of head; 6, top of head showing frontal
(/) and occipital (o) fontanels; c, dentition. C. M. 6881.

A large vertical humeral spot, chiefly above the third and fifth scale of the
lateral line; a silvery lateral band. A spot on caudal peduncle, in the young
definitely continued to the end of the middle rays.

Genus IV. Aphyocharax^" Giinther.
Aphyocharax Giinther, Proc. Zool. Soc. London, 1868, p. 245 (pusilhis).
Holoprion Eigenmann, Smithsonian Misc. Coll., Quarterly, Vol. XLV, 1903, p. 145
(agassizii) .
Type: Aphyocharax pusillus Giinther.

Elongate, slender fishes, reaching a maximum length of about 80 mm., most of
them much shorter.

'° a^irq, = a Small fish, anchovy, sardine, or Motella; xnpaf = a pointed stick, or palisade; Charax, a
genus of characid fishes with pointed teeth.

EIGENMANN: the CHEIRODONTINiE. 23

Head pointed, skull convex above, with parietal and frontal fontanel, the
latter very short, not extending beyond middle of eye in adult; mouth terminal,
greatly variable in size in different species and with age in the same species (r/. A.
dentatus); teeth all in a single series, conical, and usually with a cusp on each
margin; those of upper and lower jaw alternating and interlocking when the mouth
is closed; those of the side of the lower jaw notably smaller than the anterior
teeth; cheeks entirely covered by the suborbital; narcs close together; gill-mem-
branes free from each other; gill-rakers setiform; tongue slender, free; scales
regular, of about the same size, well imbricated, cycloid, firm; caudal naked; lateral
hne incomplete; adipose well-developed; origin of dorsal near middle of body; no
pseudotympanum; a long pore on the base of the middle caudal ray.

The genus Aphyocharax is well marked by the very strong armature of the
cheeks, the third suborbital and the single postorbital being of the same strength
and texture, and leaving but little or any of the cheek naked; the scales are firmer
than in any other genus of the subfamily and they have peculiar sculpturing.
There are two sub-parallel radial striae on the exposed part of the scales; the
circuli are well-marked near the base of the exposed portion of the scale and parallel
with the radial striae at this point, or converge toward a median line.

A. dentatus, alburnus, ery thrums, pusillus, and anisitsi form a series from the
large-mouthed dentatus with many maxillary teeth to the small-mouthed anisitsi
with few maxillary teeth. Of these A. alburnus and A. cry thrums are scarcely
distinct. A. dentatus is the Paraguayan representative, alburnus the Amazonian,
and A. ery thrums the Guianian. A. anisitsi similarly is the Paraguayan repre-
sentative, A. pusillus the Amazonian. A. melanotus probably belongs to another
genus. A. avary is probably a synonym of pusillus.

At the time A. agassizi was selected as the type of the new genus, Holoprion,
I had not seen that species. The genus was erected in view of Steindachner's
statement, "oberer Theil dcs Oberkiefers am ganzcn vorderen Rande deutlich
geziihnt." While in Vienna, I was able to examine the tjpes. It is certain that
they have several teeth along the upper anterior margin, but I was unable with
a hand-lens to detect any teeth along the distal portion of the maxillary. It
seems possible that the tji^e species of the genus Holoprion lacks the character
assigned to the genus. However, there certainly are species with this character,
viz. : Paraguay ensis, maxillaris, and possibly nattcreri, which may be referred to
Holoprion, provisionally retained as a subgenus. If a final microscopic examina-
tion of agassizi shows that it actually lacks teeth on the distal portion of the
maxillary the name Holoprion becomes an exact synonym of Aphyocharax, and a

24 MEMOIRS OF THE CARNEGIE MLSEUM.

new generic or subgeneric name will haA-e to be given to the above named
species.

Nothing is said in the original description of the teeth on the maxillary of
Cheirodon pulcher Steindachner. The description reads "Kieferzahne einreihig,
sehr klein, schlank und zahlreich." This does not apply to the genus Cheirodon,
in which genus it is placed by Steindachner, but applies very well to A. paraguayen-
sis, a species evidently very closely related to pulcher, but which has teeth along
the entire maxillary and belongs to the genus Holoprion as originally defined. It is
more than probable that pulcher also belongs here, and it is so ranked.

Range: Guiana, Amazon, and Paraguay, rare in the Uruguay basin.

Key to the Species of Aphyocharax.
a. Teeth not along the entire margin of the maxillary. (Aphyocharax.)
h. Dorsal without black.

c. Maxillary with many teeth; hooks in the male confined to the lobe of the anal; a humeral spot.

d. Mouth very large, the maxillarj' in fully grown specimens reaching to the third suborbital,

2.5 in the head; snout in the adult 3.5-3.8 in the head, but verj^ little shorter than eye;

maxillary-premaxillary border 2.1-2.33 in head; depth 3. .5-3.75; middle caudal rays pale.

4. dentatus Eigenmann & Kennedy.
dd. Mouth moderate, the maxillary not reaching the second suborbital.

e. Maxillary with 9-20 teeth extending over more than half the length of the maxillarj-;
scales 37-40.
/. Prcmaxillary with six to eight teeth, mandible with 16-20; middle caudal rays dusky;
a well-developed humeral spot; A. 17-19; depth 4.25-4.5; snout over 4 in the head;

maxillarj' 3.25 in head 5. albumus (Giinther).

ff. Premaxillary with six teeth, mandible wth about tliirteen; A. 17; middle caudal

rays pale, caudal red in life 6. erythrunis Eigenmann.

//. Maxillary with teeth along about one-third to two-fifths its length; premaxillary
with seven teeth, mandible with nine; A. 18; scales 36, 8 with tubes; head 4.5;

depth 4.5; middle caudal rays black 7. pusillus Giinther.

cc. Maxillarj' with two to fourteeth, mouth small; depth 3-3.75; scales 5 or 5.5-30 to 3.5-4.5 to 6;
mandible with nine to ten teeth; hooks in the male on nearly all anal rays; no humeral spot.

8. anisitsi Eigenmann & Kennedy.
ccc. Maxillary with four teeth; mouth moderate, maxillary reaching to below anterior margin of pupil;

depth 4.25; scales 38; A. 17 9. avary Fowler.

fcb. Dorsal, at least in male, with black. Mouth minute; posterior part of anal margined with black, the
black extending obliquely across the lobe; hooks in the male on nearly all anal rays; depth 3; A. 19
or 20; maxillary very short, convex, not reaching eye, with two teeth or none; premaxillary with

five to seven teeth; six to nine on the mandible 10. rathbuni Eigenmann.

aa. Teeth along the entire margin of the maxillary (Holuiiriuii).

g. Dorsal plain; a black border or band from the tip of the la.st anal ray to the lobe, thence obli(iuely
to the anterior rays and forward to near the ventrals; no humeral spot; origin of dorsal behind
the middle; a black caudal spot.

eigenmann: the cheirodontin^. 25

h. Scales 34 ; caudal spot not continued to the end of the middle raj's ..11. paraguayensis Eigenmann.
Ml. Scales 30; caudal spot continued to the end of the middle rays. A. 23. 12. nattereri Steindachner.
gg. Dorsal with a black spot; no caudal spot.

i. A black band along the tips of the shorter anal rays and across the middle of the elongate rays ;

A. 27; scales 30 13. agassizi Steindachner.

ii. A small, black spot near the tijjs of the first few anal rays; A. 22-23; scales 30.

14. maxillaris Ulrey.

4. Aphyocharax dentatus Eigenmann & Kennedy. (Plate IV, fig. 1.)
? Aphyocharax (Chirodon) alburnus Perugia, Ann. Mus. Civ. Storia Nat. Geneva,

(2), Vol. XVIII, 1897, p. 25 (Rio Beni; Missioni Mosetenes).
Aphyocharax dentatus Eigenmann and Kennedy, Proc. Acad. Nat. Sci. Phila., 1903,

p. 576. (Asuncion; Arroyo Trementina); Eigenmann, Ann. Carnegie Mus.,

Vol. IV, 1907, p. 126 (Corumba, Puerto Max; Rio Negro; Rio Pilcomayo);

Reports Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.

Range: Paraguay basin.

10032, I. U. M.,type, 71 mm. and 10033, 10036, 10037, 10038, I. U. M., ten.
Asuncion. Anisits.

10034 and 10035, I. U. M.; 932a & b, C. M. Aguadas near Arroyo Tremen-
tina. Anisits.

10290 and 10187, I. U. M., nine. R. Paraguay, Corumba. Anisits.

10190, I. U. M., one. Rio Paraguay, Puerto Max. Anisits.

10230, I. U. M., ten. Tributary of the Rio Negro emptying into Rio
Pilcomayo. Anisits.

6911a, C. M., one, 37 mm. Asuncion, Paraguay. Haseman.

6912a-q, C. M., seventeen, 23-72 mm. R. Paraguay, Caceres, May 26, 1909.
Haseman.

1913a-j, C. M., eleven, all females, largest 52 mm. Corumbd,, May 9, 1909.
Haseman.

6914a-e, C. M., five (one male) 56-64 mm. Corumba, April 27, 1909. Hase-
man.

7313a-j, C. M., ten, largest about 72 mm. Villa Hays, April 13, 1909. Hase-
man.

?7314a-c, C. M., three, largest about 25 mm. Santa Rita. June 12, 1909.
Haseman;

Head 4-3.8; depth 3.6-3.75 (3.4-4 in extremes); D. 11; A. 18-22; scales 5.5
to 7-36 to 42-4.5 to 6; 7 to 14 scales with pores; eye 3.5-4 in the head, 1 in snout;
interorbital 3-3.33 in the head.

26

MEMOIRS OF THE CARNEGIE MUSEUM.

Elongate, compressed-fusiform; dorsal and ventral profiles regularlj' and about
equally arched; prcventral area broad, rounded, with a median series of about
seventeen scales; predorsal area rounded, with a median series of about fourteen
scales, the regularity of the series broken near the middle; occipital process reaching
about one-eighth to one-ninth to the dorsal, bordered by two to three scales; skull
smooth, shghtly convex; fontanels narrow, the frontal fontanel reaching to above

Fig. 6. Ayhyocharax dentalus Eigenmann & Kennedy, a, outline of head, 9 nam. long, showing size of
maxillary in a specimen 68 mm. long; 1, 2, 3, suborbitals, 4, .5, postorbitals. 6, outline of top of head showing
frontal (/), and occipital (o) fontanels, c, premaxillary, d, maxillary, e, mandible, much enlarged, from a
specimen 28 mm. long, 10036, I. U. M.

the middle of the eye, its length about two and one-half times in the length of
the parietal fontanel without the groove; snout pointed, the mouth large, ter-
minal, the jaws equal; maxillary in adult reaching to the third suborbital; max-
illary-premaxillary border two and one-third times in the head, maxillary relatively
much shorter in the young; teeth recurved, slender, acutely pointed, those in the
front of the jaws with a minute cusp on each side; premaxillarj^ with seven to ten
teeth; maxiUary with nine to twenty on more than half of its edge; mandible with
thirteen to twenty-one teeth; teeth of the premaxillary and of the front of the
mandible all of about the same size; third suborbital in contact with the pre-
opercle below and behind; a single postorbital, similar to the third suborbital, its
face convex, its posterior margin in contact with the preopercle; upper part of the
opercle similar to, but smaller than the postorbital. Gill-rakers 7 + 9.

EIGENMANN: the CHEIROOONTINyE. 27

Origin of dorsal equidistant from tip of snout and base of middle caudal rays
or a little nearer the latter; dorsal truncate, tip of third to seventh ray about equal
when the fin is half closed; highest ray a little shorter than head; adipose fin small,
but well developed; caudal lobes about equal to length of head; origin of anal
under end of dorsal, last twelve rays of anal of about the same height, the third to
eighth forming a lobe two and a half times as high as the posterior rays, very
little longer than snout and eye; vcntrals not reaching anal by three or four scales,
their origin far in advance of the dorsal ; pectorals not reaching ventrals by two to
three scales.

Scales everywhere very regularly imbricate, pores developed on seven to
fourteen scales and on the last scale of the series above the lateral line series, a
long tube on the base of the middle caudal ray; sheath of scales covering the
basal fifth of the caudal lobes, the last scale on each lobe largest ; anal with not over
four scales forming a sheath for the anterior raj's ; axillarj^ scale large ; scales usually
with two sub-paraUel radials, the circuli on at least the basal part of the exposed
portion of the scale prominent above and below.

A diffuse, but quite evident, shoulder-spot; margin of caudal dusky, a silvery
lateral band; first dorsal ray dark, a few chromatophores on the membranes from
the middle of the first to the tip of the penultimate, forming a very faint, oblique
band; bases of some of the rays dusky.

Male with hooks on the third to the eighth anal ray; i. e., on the anal lobe,
which is equal to the snout and eye.

This is the largest species of the genus and is abundant in the Paraguay to
San Luiz de Caceres.

5. Aphyocharax alburnus (Giinther).

Chirodon alburnus Giinther,'^ Proc. Zool. Soc. London, 1869, p. 424, fig. 2 (Peruvian

Amazons) .
Aphyrocharax alburmis Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol.

XIV, 1891, p. 292; Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 292;

Eigenmann, Reports Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.

" GiJnther's original description is verj' brief and reads:
"D. 10. A. 20. L. lat. 37. L. transv. 11.

The height of the body is a little more than the length of the head, and one-fourth of the total (without
caudal). Upper profile of the head not concave. The pectoral does not extend to the ventral. Teeth scarcely
compressed, pointed, with a minute (microscopical) lobe on each side; there are about twelve in the upper and
eighteen in the lower jaw. Sides with an ill-defined silvery longitudinal band; the middle caudal rays blackish.

Two and a half inches long."

28 MEMOIRS OF THE CARNEGIE MUSEUM.

Range: Amazon basin.

11087, I. U. M., one, 58 mm. Rio Jurua. From British Museum.

6915a-i, C. M., four females, 47-55 mm., six males, 34-43 mm. Santarem,
Dec. 6, 9, and 15, 1909. Haseman.

20713a-b, M. C. Z., two, 37 mm.. Villa Bella. L. Agassiz. Thayer Expedition.

20813a-f, M. C. Z., six, largest 51 mm. I^a. William James. Thayer Expe-
dition.

20813a-d, C. M., four, largest 39 mm. San Joaquin, Bolivia, Sept. 4, 1909.
Haseman.

Head 4.2-4.5; depth 4.2-4.5; D. 11; A. ^3-, ¥, ¥; scales 39-40, of which 10-12
with pores; eye 3 in head, snout 4 in head, interorbital slightly larger than eye.

Maxillary always falling short of the third suborbital; maxillary-premaxillary
border three times in the head, in the largest specimen; prcmaxillary with six to
eight teeth ; maxillary with ten to sixteen teeth on over half the length of the max-
illary; mandible with eight large teeth and eight small ones on the side.

Margin of caudal and the middle rays dusky. In all other respects the
description of dentatus applies to this species.

6. Aphyocharax erythrurus Eigenmann.
Aphijocharnx erythrurus Eigenmann, Mem. Carnegie Mus., Vol. V, 1912, p. 313,

PL XLIV, fig. 4 (Rockstone, Crab Falls, and Maripicru Creek, British Guiana.)

1879a, C. M., type. 1880a-e, C. M.; 12161, I. U. M., paratypes, 28-58 mm.
Rockstone. Eigenmann.

1881a, C. M., paratype, 29 mm. Maripicru Creek. Grant.

2494a, C. M., paratype, 35 mm. Crab Falls. Eigenmann.

Head about 4; depth 3.66-4; D. 10 or 11; A. 17 or 18; scales 5-34 to 37'--3;
nine to eleven scales with pores; eye a little longer than snout; 3.5 in the head;
interorbital 3 in the head.

Maxillary-premaxillary border 2.5-2.75 in the head; six teeth in the pre-
maxillary, twelve to fourteen along the greater part of the maxillary, about thirteen
in the dentary. Middle caudal rays pale.

This species is almost identical with alburnus, but can readily be distinguished
by the pale middle caudal rays and the slightly longer maxillary.

7. Aphyocharax pusillus Giinther.
Aplnjochamx puaillm Gunthor, Proo. Zoul. Soc. Lond., 1868, p. 245 (Huallaga;
Xebcros); Cope, Proc. Acad. Nat. Sci. Phila., 1871, p. 260 (Ambyiacu); Cope,

'■- And a few on the caudal.

EIGENMANN: the CHEIRODONTINiE. 29

Proc. Am. Philas. Soc, Vol. XVII, 1878, p. 689 (Peruvian Amazon); Eigen-

mann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 55; Ulrey,

Ann. N. Y. Acad. Sci., Vol. VIII, 1885, p. 292; ? Boulenger, Ann. & Mag.

Nat. Hist. (7) Vol. II, p. 478 (Jurua)''; Fowler, Proc. Acad. Nat. Sci. Phila.,

1906, 333, fig. 22 (Ambyiacu, Peruvian Amazon.)

Range: Maranon basin; Madeira basin.

6917a, C. M. 50 mm. Palo Grande Fall, Rio Mamor^, Sept. 30, 1909. Hase-
man.

6918a-b, C. M. two, larger 58, Berlin, Bolivia, Sept. 15, 1909. Haseman.

6919a, C. M. one, 43 mm. Maciel, Rio Guapore, July 2, 1909. Haseman.

Head 4.33-4.8; depth 4-4.3; D. 11 or 12; A. 18 or 19; eye 3-3.5 in the head,
1 in snout; interorbital 2.6-3 in the length of the head.

Maxillary-premaxillary border three times in the head, maxillary about four
times; maxillary with five to eight teeth on one-third to one-fourth of the margin;
premaxillary with seven teeth; mandible with ten to sixteen. Middle caudal rays
dark.

This species differs from alburnus in the number of maxillary teeth.

8. Aphyocharax anisitsi Eigenmann & Kennedy. (Plate III, fig. 6.)
Aphyocharax anisitsi Eigenmann & Kennedy, Proc. Acad. Nat. Sci. Phila., 1903,
p. 517 (Asuncion; Campo Grande; Arroyos Trementina and Chagalalina) ;
Eigenmann, Reports Princeton Univ. Exp. Patagonia, Vol. Ill, 1910, p. 429.
Range: Paraguay basin; Cacequy, Uruguay basin.

10024, 10026, I. U. M.; 936a-b, C. M., fifteen specimens, Campo Grande.
Anisits.

6920a-k, C. M., twelve (four males), largest 35 mm., Asuncion, March 28, 1909.

Haseman.
10028, I. U. M., type, 41 mm.; 10027 & 10029, I. U. :M., three, Asuncion.
Anisits.

6921a, C. M., one, 37 mm. Puerto Suarez, Bolivia. Steinbach.
10031, I. U. M., one, Arroyo Trementina. Anisits.

10025, I. U. M., one, Arroyo Chagalalina. Anisits.

6222a-c, C. M., three, largest 32 mm. to base of caudal. Cacequy. R. Ibicuhy,

into Uruguay. Haseman.
Head 3.75^.2; depth 3-3.75; D. 10 or 11; A. ¥, \''-, ^, ^, ¥; scales 30-35,

" I have specimens of alburnus from the Jurua sent by the British Museum. It is possible that these
are some of the specimens identified a.s puxillus by Boulenger.

30

MEMOIRS OF THE CARNEGIE MUSEUM.

6 to 9 with pores; ej'^e 2.75-3.33 in the head, .5-.75 in the snout; interorbital 2.4
in the length of the head; interorbital a very little greater than eye.

About thirteen pre ventral scales, an equal number of predorsal scales; maxillary-
premaxillary border three times in the head, maxillary about two-thirds as long as the
eye. Premaxillary with six to eight teeth; maxillary with two to four, mandible
with nine to ten; mouth small, the maxillary scarcely reaching to eye; pectorals
reaching vcntrals; origin of dorsal nearer caudal than to tip of snout.

Anal and caudal sometimes margined with dark; chromatophores on the
dorsal rays; outer pectoral ray sometimes dark; no humeral spot.

Anal in the male with four, rarely more, hooks on all the rays but the first

Fig. 7. Aphyocharax anisitsi Eigenniann. a, side of head; b, c, f/, premaxillary, maxillary, and portion
of mandible of a specimen, 10029, I. U. M. 28 mm. to base of caudal.

two and the last, the hooks strongest on the posterior rays and on the middle third
of the rays.

While quite similar in general appearance to dentaius, this species differs in
many ways. It is smaller, deeper, has fewer scales, much fewer maxillary teeth,
a smaller mouth and different color. The anal in the male with hooks on practically
all the developed rays, is quite different from that of A. dentatus, which has hooks
on only the rays of the lobe.

9. Aphyocharax avary Fowler.
Aphyocharax avary Fowler, Proc. Acad. Nat. Sci., Phila., 1913, p. 532.

Known only from the type, 54 mm. long, from the Madeira River about two
hundred miles east of Long. 62° 20', Brazil.

Head 3.87; depth 4.25; D. 13; A. 17; scales forty-two, of which eleven are

eigenmann: the cheirodontin^. 31

with tubes; eleven scales between dorsal and ventrals; nineteen predorsal scales;
depth of caudal peduncle 2.4 in the length of the head; height of dorsal 1.25;
height of anal 1.66; length of pectoral 1.33; ventral 1.6.

Elongate, slender, fusiform; maxillary reaching to below anterior margin of
pupil; teeth conic, each usually with a very small or obsolete pointed basal cusp;
maxillary with about four conic teeth.

Origin of dorsal midway between posterior nostril and base of caudal; origin

Fig. 8. Aphyocharax avary Fowler. (After Fowler, Proc. Acad. Nat. So., Phila., 1913, p. 532.)

of anal behind the vertical from the base of the last dorsal rays; origin of ventrals
well before the dorsal.

A silver}^ lateral band ; humeral spot crossing third, fourth, and fifth scales of
the lateral line; dorsal with a transverse median streak. Anal broadly whitish in
front; rest of fin sprinkled with duskj^ dots, the edge of the fin dark, the dark con-
tinued across the anal lobe.

10. Aphyocharax rathbuni Eigenmann. (Plate III, fig. 5.)
Aphyocharax alburnus Eigenmann & Kennedy (won Giinther), Proc. Acad. Nat.

Sci., Phila., 1903, p. 517.
Aphyocharax anisitsi (part) Eigenmann and Kennedy, Proc. Acad. Nat. Sci.,

Phila., 1903, p. 517.
Aphyocharax rathbuni Eigenmann, Proc. U. S. Nat. Mus., Vol. XXXIII, 1907, p.

10. (Arroyo Chagalalina, ParaguajO ; Reports Princeton Univ. Exped. Pata-
gonia, Vol. Ill, 1910, p. 429.
Aphyocharax stramineus Eigenmann, Proc. U. S. Nat. Mus., Vol. XXXIII, 1907,

p. 11 (Arroyo Trementina); Eigenmann, Reports Princeton Univ. Exped.

Patagonia, Vol. Ill, 1910, p. 429.

Range : Paraguay basin.

32 MEMOIRS OF THE CARNEGIE MUSEUM.

10025, I. U. M., one, 26 mm. to base of caudal. Arroyo Chagalalina, Para-
guay basin. J. D. Anisits. Type of mthbuni.

10030, I. U. M., one, 25 mm. to base of caudal. Arroyo Trementina. J.
D. Anisits. Type of stramineus.

A close comparison of rathbuni and stramineus in the light of the study of the
group of the Cheirodontince makes it quite probable that stramineus is the female
of rathbuni.

No additional material was collected by Haseman.

Head 4; depth 3; D. 11; A. 19 or 20; scales 35, 9 between dorsal and ventrals;
eye 2.&-3 in the head, equal to the interorbital; snout about half length of eye.

Elongate, compressed; preventral area rounded, without a distinct median
series of scales, of which there are eleven between ventrals and the isthmus; pre-
dorsal area rounded, with about fourteen scales, of which about nine in front of
the dorsal are in a median series; occipital process very short, reaching about

Fig. 9. Aphyocharax rathbuni Eigenmarm. Greatly enlarged.

one-seventh to the dorsal; frontal fontanel about half as long as the parietal with
its groove; second suborbital in contact with the lower limb of the preopercle
along its entire margin; a naked wedge behind it; postorbital strong, its margin
more convex in the male than in the female, having a naked area around its entire
distal margin; lateral line tubes on the postorbital and on the third suborbital
strong; mouth very small, the maxillary very short, its margin very convex, not
reaching the anterior margin of the eye; premaxillary with about five teeth, maxil-
lary with one to three; mandible with six to nine teeth, the first three rapidly
graduate.

Origin of dorsal a little nearer base of caudal than tip of snout; origin of anal
under dorsal; anal with a shght lobe, the end of the fin rounded; most of the anal

eigenmann: the cheirodontin-s;. 33

rays of the male with a few hooks; ventrals reaching to or nearly to the anal;
pectorals not reaching to ventrals.

Seven or eight scales with pores; scales firm, mostly with two slightly di-
vergent radial striic; caudal naked, the scales extending but little on the base of
the lobes, the last scale on each lobe large; anal naked.

No humeral or caudal spots; back thickly dusted; dorsal dusted Uke the back;
quite black in the male, especially along its base and posterior part; margin of
caudal dusky; margin of anal forward to the lobe black or dusky, a narrow dusky
band extending obliquely across the lobe to the basal third; opercle with a few
chromatophores, largest near its anterior margin; the color everj^where more
intense in the male. The color of the anal is evidently much like that of A. agassizi.

Closely allied to A. anisitsi, the mouth still smaller.

11. Aphyocharax paraguayensis sp. nov. (Plate II, fig. 2.)
6906a, C. M. Type, 25 mm. 6907, C. M., paratype, 20 mm. Rio Paraguay,

Caceres, May 24, 1909. Haseman.
Head 4; depth 3.5-3.8; D. 10 or 11; A. 22; scales 5 + 29; eye about three
in the head, a trifle less than interorbital.

Elongate, dorsal and ventral profiles ahke; preventral area rounded, without
a distinct median series of scales, about fourteen rows; predorsal area rounded.

Fig. 10. Dentition of Aphyocharax paraguayensis E\genmixnn. 6906, C. M.

with a perfect median series of thirteen scales; occipital process nearly equilateral,
reaching about one-seventh to the dorsal, bordered by one and one-half scales;
frontal fontanel reaching to near anterior margin of eye, but little, if any, shorter
than the parietal without the groove; third suborbital in contact with the pre-

34 MEMOIRS OF THE CARNEGIE MUSEUM.

opercle in front and behind; a single postorbital, its lower half in contact with
the vertical limb of the preopcrcle, a naked margin behind its upper half; no tubes
on the suborbital or postorbital; mouth large, verj- oblique, the chin entering the
profile; the maxiUary-premaxillarj' border a gentle curve, longer than eye; maxillary
reaching beyond suture between second and third suborbital; maxillary
with thirteen conical teeth along practically its entire margin; premaxillary with
six slightly graduate teeth with a small notch on each side near the tip of each
tooth; mandible with twelve graduate teeth along the greater part of its margin,
similar to those of the premaxillary, the lateral ones simply conic. Gill-rakers
4 + 7.

Origin of dorsal equidistant from tip of snout and near end of middle
caudal raj's; the highest ray a little shorter than head; origin of anal under
anterior part of dorsal; ventrals not quite reaching anal, pectorals a little beyond
origin of ventrals.

Each scale with two sub-parallel radial striae dividing the scale into three
fields of about equal height; caudal naked; pores on but few scales.

A sub-triangular caudal spot, its base across the entire caudal peduncle, its
tip on the basal third of the middle caudal rays; dorsal nearlj^ evenly peppered;
sides of head and abdomen silvery; chin, upper lip, and sides peppered, the pepper-
ing densest along the back and along the base of the anal, the spots becoming larger
along the base of the anterior anal rays, and continued forward to the ventrals;
a dark band beginning at the base of the first to fourth anal rays, extends
obliquel}^ to the tip of the sixth and along the margin of the succeeding rays;
middle caudal rays without chromatophores, the lobes faintly peppered.

12. Aphyocharax nattereri Steindachner.
Tetragonopterus diaphanus Cope (part), Proc. Am. Philos. Soc, Vol. XVII, 1878,

p. 691 (Peruvian Amazon).
Cheirodon pidcher Steindachner, Flussf. Siidam., Vol. IV, 1882, p. 39 (Villa Bella);

Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 54;

Fowler, Proc. Acad. Nat. Sci. Phila., 1906, p. 332, fig. 21 (based on Cope's

specimens mentioned above) .
Cheirodon nattereri Steindachner, Anz. Akad. Wiss., Wien, 1882, p. 180 (Villa

Bella); Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891,

p. 54; Ulrey (part), Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 291 (Para);

?Boulenger, Boll. Mus. Univ. Torino, Vol. XIV, 1900 (Urucum, Matto

Grosso); Eigenmann, Reports Princeton Univ. Exped. Patagonia, Vol. Ill,

1910, p. 429.

EIGENMANN: the CHEIRODONTINiE. 35

Cheirodon steindachneri Eigenmann & Eigenmann, Proc. U. S. N. M., Vol. XIV,

1891, p. 54.

Range : Amazons from Para to Peru.

The names C. pulcher and C. natter eri were proposed for the same species, the
latter being substituted by Steindachner for the name -pulcher, which was pre-
occupied. Without knowing that the specific name nattereri had been substituted
by Steindachner, the name steindachneri was also proposed bj" the writer for the
pre-occupied pulcher. It is a pure synonym.

It is quite certain that some at least of Uhey's specimens belong to the genus
Astyanax. It also seems doubtful whether the specimens figured by Fowler are
A. nattereri, since they distinctly differ in color. I have no specimens at hand; the
description of Steindachner may be in part reproduced :

[P. 39.] " Korperform sehr gestreckt. Alburn ?/.s-artig. Riicken- und Bauchlinie
gleichformig, ausserst schwach gebogen.

"Seitenlinie unvoUstandig. Dorsale mit ihrem ersten Strahle eben so weit
von der Caudale wie vom hinteren Augenrande entfernt, somit nicht unbetrachtlich
weit hinter der Mitte der Korperlange beginnend. Ventrale vor der iMitte der
Korperlange eingelenkt.

"Grosste Korperhohe c. 3J^-3^ mal, Kopflange c. 33/^-3J^ mal in der
Korperlange enthalten," imd der Schnauzenlange bis zur Kinnspitze gemessen wie
der Stirnbreite gleich.

"Kopf nach vorne zugespitzt. Mundspalte sehr schrage gesteUt, Unterkiefer
nach vorne vorspringend. Kieferzahne einreihig, sehr klein, schlank und zahlreich.
Knochen des Augenringes die niedrige Wangengegend voUkommen deckend.

"Dorsale nach oben zugespitzt, an Hohe etwas der Kopflange nachstehcnd.
Pectorale bis zur Basis der Ventralen zuriickreichend, an Liinge cin wenig geringer
als die Hohe der Riickenflosse.

[P. 40.] "Ventrale mit ihrer Spitze den Beginn der Anale nahezu erreichend.

"Anale in ihrem vordercn Theile massig lappenformig erhoht.

" Schuppen klein, ziemlich festsitzend. Die Scitcnlinie durchbohrt nur 4-6
Schuppen am Vorderrumpfe.

" Rumpf goldgelb. Humeralfleck ausnahmslos fehlend. Ein intensiv schwarz-
violctter, hiiufig rhombenformigcr Fleck an und vor der Basis der Caudale, nach
hinten iiber die mittleren Caudalstrahlen bis zu deren hinterem Rande sich
fortsetzend.

" E\'ideiitly there is an omission here. Probably in the manuscript Dr. Steindachner Iiad stated that
the eye is contained so many times in the head, but the statement was omitted by the printer.

36 MEMOIRS OF THE CARNEGIE MUSEUM.

"Ein hellgelber Fleck am oberen und unteren Caudallappen unmittelbar
hinter dem Caudalflcck. Ein gleichfalls intensiv violetter Streif am Bauch ein
wenig hinter dor Insertionsstelle der ^^entralen beginnend und sich langs der
ganzen Basis der Anale hinziehend. Ein Nebenast dieses Streifens zieht, ein
wenig an Breite zunehmend (daher bindenalinlich), von der Basis der 3^ ersten
Analstralilen schrage nach hinten und unten zum unteren Rande des 6. und 7.
Analstrahles und bildet hierauf einen schmalen Saum am freien Rande der folgenden
Analstrahlen.

"D. 9-10. A. 23. L. lat. c. 30. L. tr. 4/1/3.

"Zahlreiche Exemplare, nur bis zu 25-26 Mm. in der Totallange, von Villa
Bella (Amazonenstrom)."

13. Aphyocharax agassizi (Steindachner).
Cheirodon agassizii Steindachner, Flussf. Siidam., Vol. IV, 1882, p. 38 (Jatuarana);

Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 54.
Aphyocharax agassizii Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 293.
Holoprion agassizii Eigenmann, Smiths. Misc. Quarterly, Vol. XLV, 1903, p. 145;

Reports Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.

Range: Jatuarana, Amazon basin.

I have recognized no specimens of this species in the collections at my disposal
and add the original description :

" Korperform sehr gestreckt. Seitenlinie unvollstandig; ein braunlichvioletter
Fleck am vorderen Theile der oberen Hohenhalfte der Dorsale, hoher als lang.

"Riicken- und Bauchlinie sehr schwach gebogen, erstere ein wenig rascher
zur Dorsale ansteigend, als letztere bis zur Ventrale sich senkt. Dorsale in der
Mitte der Korperlange imd nur wenig hinter der Basis der Ventralen in verticaler
Richtung beginnend. Anale im vorderen Theile erhoht, lappenformig liber den
Rest der Flosse vorragend. Humeralfleck sehr undeuthch; Caudalfleck fehlend,
Kopfliinge mehr als SJ-amal, grosste Rumpfhohe 3mal in der Korperlange.

" Augendiameter etwas weniger als 3mal, Stirnbreite 33^mal, Schnauzen-
liinge gleichfalls 33^'2mal in der Kopfiange enthalten. Kieferzahne zahlreich,
schlank, verhaltnissmassig sehr klein, spitz, mit kurzen Nebenzacken, im Zwischen-
kiefer einreihig.

"Oberer Theil des Oberkiefers am ganzen vorderen Rande deutlich gezahnt.

"Obere Profillinie des Kopfes grade, nur wenig nach hinten ansteigend.

"Pectorale imd Ventrale nach hinten zugespitzt; letstere iiberragt mit ihrer
Spitze den Beginn der Anale bei einem Exemplare nicht unbedeutend, erstere
erreicht nur die Basis der Ventralen.

eigenman: the cheirodontin^. 37

"Dorsaie an Hohe einer Kopfliinge gleich, Ventrale um die Lange der Schnauze
kiirzer als der Kopf. Die Seitenlinie durchbohrt 7-8 Schuppen am Rumpfe.

"Der untere Rand der kurzen Analstrahlen ist dunkelviolett gesaumt, und
diese Fiirbung setzt sich strichformig horizontal nach vorn fort, so dass der vordcre
erhohte Theil der Anale durch diesen violetten Streif der Hohe nach halbirt
erscheint. Der vordere lange Randstrahl der Anale (der dritte der ganzen Flosse)
zeigt eine milchweisse Fiirbung.

"Rumpfseiten goldgelb, silbergraue Seitenbinde nicht scharf abgegrenzt.

"D. 11. A. 27. P. 13 (14). V. 8. L. lat. 30 (bis zur Caud.) L. tr. 5/1/3.

"Zwei Exemplare, jedes c. 40 mm. lang, von Jatuarana und ein Geschenk des
Herrn Prof. L. Agassiz, dessen Andenken ich diese interessante Art widme."

14. Aphyocharax maxillaris Ulrey.
Aphyocharax maxillaris Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 293

(Brazil).
Holoprion maxillaris Eigenmann, Reports Princeton Univ. Exped. Patagonia, Vol.

Ill, 1910, p. 429.

Range : Brazil, definite locality not known, probably from the lower Amazon.

This species is known only from the types.

Head 3.5; depth 3-3.5; D. 11 ; A. 22-23, scales 6 + 24. Eye 2.33 in the head.

Snout very short, the maxillary extending beyond anterior margin of eye;
premaxillary with about ten teeth, the median four three-pointed; mandible with a
few conical teeth.

Origin of dorsal equidistant from tip of snoutand base of caudal; pectorals
reaching beyond origin of ventrals; the latter to the anal.

A smaU circular humeral spot, sometimes reduced to two or three color-cells.
A large black spot on the upper half of the first dorsal rays, the tips of these rays
white; a smaU black spot near tip of first few anal rays.

Genus V. Prionobrama^^ Fowler.
Prionobrama Fowler, Proc. Acad. Nat. Sci. Phila., 1913, p. 534 (madeiroe).
Bleptonema Eigenmann, Indiana University Studies, No. 20, 1914, p. 44 (paraguay-
ensis).

Type: Prionobrama madeirw Fowler = Aphyocharax filigerus Cope.
General appearance of Gephyrocliarax. Teeth tricuspid and conical in a single
series on mandible, premaxillary, and along entire edge of maxillary; origin of
"xpiuv = a saw; /Jpd^o = a bream.

38 MEMOIRS OF THE CARNEGIE MUSEUM.

dorsal behind the middle, about over the vertical from the origin of the anal;
adipose fin well -developed; anal falcate, with fewer than forty rays, its origin
nearer caudal than snout, first and second developed rays filigerous, curved;
pectorals placed low, long and falcate, their margins nearly along the edge of the
compressed belly when the fin is closed; caudal naked; lateral line incomplete;
mouth very oblique; profile from tip of snout to near dorsal straight; two post-
orbitals, similar to those in Aphyocharax, the lower large, the upper minute, some-
times a minute triangular wedge between the third suborbital and the postorbital,
representing the lower postorbital of other genera; third suborbital covering the
entire cheek; no well-defined pseudotympanum.

Key to the Species of Prionobrama.
a. Lateral line 35-38; eight or nine scales between ventrals and dorsal; anal rays 29-34.

15. paraguayensis (Eigenmann).
aa. Lateral line 38-41 ; nine or ten scales between ventrals and dorsal; anal rays usually 32.

16. filigera (Cope).

15. Prionobrama paraguayensis (Eigenmann). (Plate IV, fig. 5.)
Bleptoyiema paraguayensis Eigenmann, Indiana University Studies, No. 20, 1914,

p. 44 (Corumba).

Range : Uruguay and Paraguay basins.

6884a-b, C. M., two, largest about 50 mm. Corumba, May 9, 1909. Haseman.

6885a, C. M., one, about 42 mm. Puerto Suarez, May 6, 1909. Haseman.

6886a & b, C. M., two, largest 45 mm. Villa Hays, April 11, 1909. Haseman.

6887a-c, C. M., three, largest 42 mm. Asuncion, March 29, 1909. Haseman.

6888a-j, C. M., ten, largest 49 mm. Arequa, April 8, 1909. Haseman.

847, M. C. Z., four, largest 35 mm. Uruguay River. Wyman.

5499, C. M., type, 40 mm. to base of caudal; 5499, C. M., paratypes, six,
largest over 50 mm. Corumbd, April 27, 1909. Haseman.

Head 4.66-5; depth 3.33; D. 10, rarely 11; A. 29-34; lateral fine 8 to 11 + 26
to 28 = 35 to 38; eight or nine scales between ventrals and dorsal; eye 3 in the
head, about equal to interorbital.

Elongate, compressed, breast with a series of large median scales; belly
between pectorals and ventrals trenchant, the margins of the scales of one side
bent over the middle line, no median series of scales; predorsal with a median
series of about sixteen scales, the series less regular near the occipital process,
which extends about one-eighth of the way to the dorsal; skull smooth, convex,
frontal fontanel large, triangular, a little more than half the length of the parietal;

eigenmann: the cheirodontin^. 39

second suborbital in contact with both the posterior and the lower limb of the pre-
opercle; mouth very oblique, maxillary-premaxillary border a little more than
orbital length; sixteen to twenty teeth on the maxillary, those on the posterior
half larger, pointing backward and outward; seven premaxillary teeth; mandible
with six or seven tricuspid teeth, the first and last distinctly larger than those
between; in addition to these six or seven larger teeth several minute teeth appear
posteriorly.

Origin of dorsal a little nearer to base of middle caudal rays than to the eye;
origin of anal in front of or under the dorsal; first developed anal ray heavy and
much prolonged, the second less so; outer ventral ray filiform; extending beyond
the origin of the anal, pectorals to near middle of the ventrals; pectorals placed
low, their base oblique, their shortest ray about one-half of the outer ray, which is
similar to the outer ventral and first developed anal raJ^

Scales everywhere regularly imbricate, with few radial strise; a series of verj^
small scales along the base of anal, caudal with a few scales at the base of the
lobes; axillary scales small.

No definite markings, margin of anal in the male dusky.

16. Prionobrama filigera (Cope). (Plate IV, fig. 4.)
AphyocJiarax filigerus Cope, Proc. Am. Philos. Soc, 1870, p. 564 (Pebas) ; Eigen-
mann & Eigenmann, Proc. U. S. Nat. INIus., Vol. XIV, 1891, p. 55; Fowler,

Proc. Acad. Nat. Sci. Phila., 1906, p. 334, fig. 23 (Pebas); Eigenmann, Reports

Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.
Paragoniates mulleri Steindachner, Ichthj'ol. Beitr., Vol. V, 1876, p. 72 (Obidos).
Prionobrama madeirce Fowler, Proc. Acad. Nat. Sci. Phila., 1913, p. 534, fig. 9.

(Tributary of Rio Madeira near Porto Velho, Brazil.)
Blejitonema amazoni Eigenmann, Indiana Universitj" Studies, No. 20, 1914, p. 44

(Santarem). \/

Aphyocharax analis Nichols, Bull. Am. Mus. Nat. Hist., Vol. XXXIV, 1915, p. 127

(Manaos).

Range : Amazons from Pebas to Villa Bella, Madeira basin.

5499a, C. M. Type of amazoni, 54 mm. 5599a-c, C. M., paratypes, 50-55 mm.
Santarem. Dec. 9, 1909. Haseman.

21188, M. C. Z.,""' about 58 mm. Villa Bella, Jan. 1866. L. Agassiz.

21182, M. C. Z., twelve, largest 53 mm. Villa Bella, Jan. 1866. L. Agassiz.

21248, M. C. Z., seven, largest 51 mm. Iga. Jan. 1866. William James.

" Anal filament reaching to base of last anal ray. A. 30; 1.1. 39.

40

MEMOIRS OF THE CARNEGIE MUSEUM.

21231, M. C. Z., two, larger 50 mm. Hyavary. D. Bourget.
21234, M. C. Z., twenty-one, largest 55 mm. Tabatinga. Bourget.
6889a, C. M., one, 50 mm. Santarem, Dec. 9, 1909. Haseman.
6890a-q, C. M., seventeen, largest 50 mm. Santarem, Dec. 15, 1909. Haseman.
6891a-n, C. M., fourteen, largest 60 mm. MUa Bella, Oct. 5, 1909. Haseman.
6892a-c, C. M., one, 54 mm. San Joaquin, Sept. 6, 1909. Haseman.
6923a, C. M., one, 50 mm. San Antonio de Rio Madeira, Nov. 3, 1909. Hase-
man. «
This species is very similar to yaraguayenstf

Fig. U. Priorwhrama filigera (Cope), a, side of head; h, top of head; c, d, e, the premaxillary, maxillary
and portion of mandible; c', premaxillary of the other side; e', outline of entire mandible showing the extent of
dentigerous portion, /, another mandible.

The scales are eight to fourteen (usually eleven) + twent}'-six to thirty =
thirty-eight to forty-one, nine or ten between ventrals and dorsal; the origin of the
dorsal is equidistant from the base of the middle caudal ra^'s and the anterior margin
of the eye, above the origin of the anal.

Number of anal rays: 31, 32, 34, 35, 36, 37
Number of individuals: 3 9 2 111

Genus VI. Paragoniates'^ Steindachner.
Paragoniates Steindachner, IchtM'ol. Bcitr., Vol. V, 1876, p. 69.

Type : Paragoniates alhurnus Steindachner.

Teeth mostly tricuspid, the lateral cusps minute, very much smaller than
the median cusp; teeth all in a single series, those of the premaxillary anteriorly

" TopA = besides; aywviikTTis, 6 = a nervous person; Agoniates, a genus of fishes.

eigenmann: the cheirodontin^. 41

crowded, the second, and sometimes the fourth, more or less crowded out of line
with the rest, suggesting an incipient second series; teeth along the entire edge
of the maxillary. Origin of dorsal behind the middle; origin of anal about in the
middle; adipose fin well -developed; anal fin without a lobe, its margin nearly
str ight; pectorals placed low, foliate, their margins nearly along edge of belly,
when the fin is closed; caudal naked. Lateral line incomplete. Mouth large,
oblique. Three postorbitals, covering entire postorbital area, the middle one the
largest.

17. Paragoniates alburnus Steindachner. (Plate IV, fig. 2.)
Paragoniates alburnus Steindachner, Sb. Akad. Wiss. Wien, LXXIV, Ichthyol.

Beitr., Vol. V, 1876, p. 69, pi. VIII, fig. 3 (Teffe); Boulenger, Proc. Zool.

Soc, 1887, p. 281 (Canelos); Eigenmann, Report Princeton Univ. Exped.

Patagonia, Vol. Ill, 1910, p. 441.

Range : Amazon basin above Teffe.

7315a-b, C. M., two, 70 and 86 mm. Villa Bella, Oct. 5, 1909. Haseman.

7316a, C. M., one, 73 mm. Santarem, Dec. 15, 1909. Haseman.

Steindachner's diagnosis of this species reads:

"Mundspalte sehr lang, hinteres Ende des vollstandig bezahnten Oberkiefers
bis hinter die Augenmitte bei geschlossenem Munde in verticaler Richtung sich
erstreckend. Wangen vollstandig von den Knochen des Suborbitalringes iiber-
deckt. Korperhohe 2-3/4mal, Kopfliinge mehr als 4-l/3mal in der Korpcrljinge,
Schnauzenlange circa 3-2/3mal, Stirnbreite circa 3mal, Augendiameter circa 3mal,
Lange der Mundspalte zwischen l-3/4-l-4/5mal in der Kopflange enthalten.
Pectorale lang, iiber die Insertionsstelle der Ventrale, letztere iibcr den Beginn der
Anale zuriickreichend. Fettflosse sehr klein; Dorsale in verticaler Richtung circa
iiber dem 7. oder 8. Analstrahle beginnend. Seitenlinic noch vor dem Beginn
der Anale endigend. Kiemenspalte lang; VcrbindungshJiute der Kicmcnstrahlcn
mit dem Isthmus nicht verwachsen und untcr dor Kchle noch gespalten. Rcchen-
zahne der Kiemenbogen schlank, locker gestellt. Ein grosser, nicht scharf ausge-
priigter, braunlichcr Fleck am Schwanze."

Head 4.75; depth 3; D. 11; A. 44-48; scales 6 or 7-46-4 or 5, thirteen to
seventeen with pores; eye a little greater than snout, 3 in the head, equal to, or a
little less than, the interorbital ; caudal i^eduncle deeper than long.

Compressed; the ventral profile nearly regularly arched from chin to end of
anal; dorsal profile more gently and less regularh^ arched; prcventral area com-
pressed, trenchant, the scales of the two sides narrowly bent over the mid-ventral
ridge; about twenty-nine predorsal scales; a regular median series extending from

42 MEMOIRS OF THE CARNEGIE MUSEUM.

the dorsal some distance forward, but the scales irregular anteriorly; occipital
process short, only one-eighth of the distance from its base to the dorsal, bordered
by three scales; frontal fontanel reaching at least to above the anterior margin of
the pupil, entirely separating the frontals in the smaller specimen; snout pointed;
the mouth large; maxillary slender, extending beyond the suture between the
second and third suborbitals; premaxillary with seven teeth; maxillary with about
twenty teeth along its entire edge, tricuspid in the largest specimen, in the smaller
the upper ones similar to those of the premaxillary, the lower ones conical; dentary
with seven to nine tricuspid teeth and about fourteen minute ones on the sides,
conical in the smallest specimen, mainly tricuspid in the largest. Gill-rakers 7 + 11.

Origin of dorsal equidistant from tip of snout and a point beyond the tip of
the middle caudal rays; height of dorsal about four times in the length; adipose
fin small; caudal forked, the lobes 3.5-4 in the length; origin of anal equidistant
from the base of the last ray and some portion of the eye; anal without indication
of a lobe, its margin slightly convex or straight; ventrals reaching beyond origin
of anal; pectorals beyond base of ventrals.

Lateral line developed on thirteen to seventeen scales; scales with one to four

radial striae; scales of the sides continued downward to form an anal sheath of

from one to three series of scales free from the fin; scales on the end of the caudal

peduncle irregularly arranged; caudal naked; a round or oval spot on the end of

the caudal peduncle, not continued on the sides or on the fin. No other definite

markings.

Genus VII. Leptagoniates^^ Boulenger.

Leptagoniates Boulenger, Proc. Zool. Soc, 1887, p. 281.

Type: Leptagoyiiates steindachneri Boulenger.

Premaxillary, maxillary, and mandible with a single series of tricuspid teeth;
origin of anal far in advance of origin of dorsal, equidistant from tip of snout and
base of last dorsal ray; lateral line complete; adipose fin small.

I am in doubt whether in the final analysis this genus will remain associated
with the Cheirodontinse.

18. Leptagoniates steindachneri Boulenger. (Plate IV, fig. 3.)
Leptagoniates steindachneri Boulenger, I. c, p. 281, pi. XXIII, fig. 3 (Sarayacu,

Peru); Eigenmann, Reports Princeton Univ. Exped. Patagonia, Vol. Ill,

1910, p. 441.

This species is known only from the type, 95 mm. long, in the British Museum.
I append the description given bj^ Boulenger, I. c. :

w XeTTTos = thin; Agoniates, a genus of fishes.

eigenmann: the cheirodontin^. 43

"D. 10; A. 70; V. 8; P. 12; scales 7-47-7.

"The depth of the body is one-fourth of the total length (without caudal),
the length of the head one-sixth. ]\Iandible strongly projecting beyond the
mouth; maxillary not reaching below the anterior border of the eye; premaxillary
teeth 15, maxillary (on each side) 11, mandibular 14; mandibular teeth largest,
maxillary smallest. The diameter of the eye equals nearly two-fifths the length
of the head, and exceeds the width of the interorbital space. The pectoral fins
reach nearly the extremity of the ventrals, which are small; the dorsal originates
above the 23d anal ray. Colourless; sides of head and a lateral band above the
lateral line silvery."

Genus VIII. Phanagoniates Eigenmann and Wilson.'^
Phenagoniates Eigenmann & Wilson, Indiana University Studies, No. 19, 1914, p. 2.

Type: Phanagoniates wilsoni Eigenmann.

Mouth minute, teeth in a single series in each jaw, tricuspid, except in posterior
part of maxillary, where they are conical, gill-opening wide, much compressed; chest
not trenchant; pectorals large, reaching to middle of ventrals; anal very long, its
origin far in advance of the dorsal; dorsal a little behind middle of body. No adi-
pose fin, lateral line incomplete.

"19. Phanagoniates macrolepis (jMeek & Hildebrand).
Roeboides ^nacrolepis ]\Ieek & Hildebrand, Field :Mus. Publ. Zool. Ser., vol. X, 1913,

p. 84 (Rio Cupe, Boca de Cupe, Rio Tuyra).

5354, C. I\I., type, 41 mm. ; paratypes, 13030, 1. U. ^L 7, 21-38 mm. Manigru.
Charles Wilson.

5355a, C. M., paratype, 30 mm. Certegui. Charles Wilson.

5356a, C. M., 13031, I. U. AI., paratypes, 30 and 37 mm. Rio Truando.
Charles AVilson.

Head 4.6; depth 3.33; D. 9; A. 53-55. Scales 7-7 + 34-7 (9 + 35 in one),
Eye 2.2 in the head.

Much compressed, dorsal profile highest at origin of dorsal, ventral profile
deepest at origin of anal; preventral area rounded, without distinct median series
of scales; occipital process about as broad as long; occipital fontanel much wider
and twice as long as the parietal, cheeks narrow and long, entirely covered by the
second suborbital; the mouth very small, the maxillary not reaching to the eye;
lower jaw with nine teeth on each side, premaxillary with six, maxillary with eight,

" •t'aviK = bright. The name should have been printed Phanagoniates in my paper, Indiana University
Studies, No. 19, and I herewith correct the spelling.

44 MEMOIRS OF THE CARNEGIE MUSEUM.

the first four tricuspid, the last four conical. The first four forming a continuous
series with those of the premaxillary the four conical ones on the distally curved
portion of the bone. Gill-rakers about 5 + 8.

Scales thin, the margins obscure, a single row of scales along the base of the
anal rays; a few scales along the base of the caudal lobes.

Origin of dorsal slightly behind the middle of body; height of dorsal equal
to length of head; caudal lobes about equal to the height of the dorsal; origin
of anal about equidistant from the snout and origin of its last third; ventrals small,
reaching the anal; pectorals equal to the head less snout, reaching to middle of
ventrals.

Translucent, a median dusky band along middle of caudal peduncle, fading
out forward and continued narrowly on middle caudal rays; scales of back faintly
marked with chromatophores, which become restricted to the margin of the scales
on the upper part of the back. Chin and maxillary black, sometimes a dark streak
back from upper part of gill-opening.

Genus IX. Parecbasis-" Eigenmann.
Parechasis Eigenmann, Indiana University Studies, No. 20, 1914, p. 45.

Type : Parecbasis cydolepis Eigenmann.

Teeth tricuspid, in a single series on anterior part of mandible and premaxillary,
none on the maxillary or sides of the mandible; upper margin of the maxillary
for its entire length heavy, then passing abruptly into a broad, thin, blade-like
expanded portion extending to the convex free margin; sides of mandible raised;
adipose fin well-developed; caudal partly scaled; lateral line complete. Origin
of the dorsal in front of the middle. Cheeks entirely covered by the third sub-
orbital, no apparent pseudotympanum; frontal fontanel very short.

20. Parecbasis cyclolepis Eigenmann. (Plate V, fig. 2.)
Parecbasis cyclolejns Eigenmann, Indiana University Studies, No. 20, 1914, p. 45.
Range : Madeira and Amazons.

5495, C. M., type, 74 mm.; 5496, C. M., paratype, 80 mm. San Antonio de

Rio Madeira, Nov. 3, 1909. Haseman. (Two other specimens from the

same place taken by the same collector at the same time have been placed

in exchange in the Museum of the Indiana University.)

6893a, C. M. 50 mm. to end of lateral line. Santarem, Dec. 9, 1909. Haseman.

6894a-c, C. M., 3, largest 78 mm., San Joaquin, Sept. 6, 1909. Haseman.

^'' TraptK^aais, ij = a goiDg out aside from.

eigenmann: the cheirodontin^.

45

Head 4; depth 2.75-3; D. 11; A. 24-26; scales 6 or 7-38 to 40-5; eye 2.75-3 +
in the head, equal to interorbital.

Compressed, fusiform in outline, the dorsal and ventral outlines cquallj'
symmetrically curved; preventral area rounded, with a nearly complete median
series of fourteen scales, predorsal area narrowly rounded with a median series of
ten scales; occipital process bordered by four scales, extending one-fourth to dorsal;
skull convex in cross-section; frontal fontanel 2.25 in the parietal; third suborbital
in contact with both the vertical and horizontal limb of the preopercle, but leaving

Fig. 12. Parecbasis cyclolepis Eigenmann. a, outline of head; 6, outline of top of head, showing frontal

(/) and occipital (o) fontanels; c, prcmaxillary; d, dentary, teeth greatly enlarged ; c, /, g, prema.\illary, maxillary,
and mandible in outline, moderately enlarged.

a narrow angle below its anterior edge; maxillary reaching to just below eye or not
quite so far; mouth clupeoid, the premaxillary transverse, without an antero-
posterior extent; teeth minute, confined to the premaxillary and but little more than
the portion of the mandible in contact with it when the mouth is closed.

Origin of dorsal equidistant from tip of snout and end of adipose or a httle
nearer the latter; dorsal falcate, its highest ray exceeding length of head; anal

46 MEMOIRS OF THE CARNEGIE MUSEUM.

omarginatc, its origin below some part of the last dorsal ray, its base greater than
length of head; origin of ventral below origin of dorsal, just reaching anal, or a
little shorter; pectorals short, just about reaching ventrals.

Scales thin, the margins convex, with many radial striae; lateral line but little
decurved; anal naked; caudal lobes scaled for one-fourth to one-third of their
length.

A small, but conspicuous humeral spot, about equal to the size of the pupil,
over the fourth scale of the lateral line; middle caudal rays faintly peppered, or a
faint dusky streak parallel with the margin in the middle and the upper lobe of
the caudal, the rays beyond them dotted.

Genus X. Leptobrycon-' gen. nov.

Type : Leptobrycon jatuaranoe Eigcnmann.

Very similar to Parecbasis. Anal short, the highest ray, the fourth, extending
beyond the tip of the last; lateral line short; mouth very large, the premaxillary
very feeble, the maxillary very large, the upper margin thickened; lower jaw
scoop-shaped, the sides raised; teeth numerous (fourteen in the premaxillary),
feeble, conical, none on the maxillary, or on the raised part of the mandible; cheeks
partlj^ naked; postorbitals three, covering most of the postorbital area; no pseudo-
tympanum; both fontanels large; adipose well-developed.

21. Leptobrycon jatuaranae Eigenmann sp. nov. (Plate VI, fig. 1.)
20952, M. C. Z., type, 29 mm. to base of caudal. Jatuarana. Navez.
Head 3.75; depth 3.5; D. 11; A. 14; scales ?. Eye 2.5 in the head con-
siderably larger than the interorbital; occipital reaching about one-sixth to the
dorsal; frontal fontanel much narrower than the parietal, its length about 1.25
in the length of the parietal; interorbital nearly flat; maxillary very large, slightly
longer than the ej'c, reaching to below the pupil, its front margin quite convex, its
proximal margin slightly concave and thickened; premaxillary altogether transverse,
each premaxillary with about fourteen minute, apparently conical teeth, without
lateral notches. Mandib'-c with minute teeth on its anterior edge, the side of the
jaw upturned. Third suborbital narrowly in contact with the preopercle below.
A small naked angle below its anterior edge. A narrow naked strip behind it.
Gill-rakers 8 + 17, long and slender, the longest more than half length of eye.

Origin of dorsal equidistant from tip of snout and base of caudal; origin of
anal behind the vertical from last dorsal ray; base of anal not much longer than eye,

^' XeiTos, small, or delicate; Brijcon, a related genus of the CharacidiE, from Ppixoi, to eat greedily.

eigenmann: the cheirodontin^. 47

its highest ray reaching beyond tip of last ray; ventrals reaching anal; pectorals
small, not reaching ventrals, whose origin is below origin of dorsal. Scales with
numerous parallel radial striae; caudal naked, lateral line incomplete. Scales
mostly lost.

Color uniform; a silvery lateral stripe.

This species is readily distinguished from uruguayanoe by its numerous teeth
and the very short anal.

This specimen is very small and in bad repair, but its characters are so well
marked that there will be no difficulty in recognizing the species.

Genus XI. Aphyodite-^ Eigenmann.

Type : Aphyodite grammica Eigenmann, Mem. Cam. Mus., Vol. V, 1912, p. 314.

Teeth minute, conical, or but feebly notched, seven on the premaxillary,
fifteen or more on the mandible, none on the maxillary; premaxillary feeble, maxil-
lary considerably larger, its outer margin convex; its inner margin concave and
slightly thickened; sides of mandible much raised; adipose fin well developed;
caudal lobes scaled to near their tips; cheeks covered by the third suborbital;
postorbitals in three or four pieces, covering about half the \\adth of the postorbital
area, the tubes prominent; frontal fontanel about half as long as the parietal; no
pseudotympanum ; anal long.

Distinguished from the related genera, Macropsohrycon, Megalamphodus, and
in fact from all the other genera of the subfamily by the scaled caudal.

22. Aphyodite grammica Eigenmann.
Aphyodite grammica Eigenmann, Mem. Carnegie Mus., Vol. V, 1912, p. 314, PI.

XLIV, fig. 5 (Konawaruk).

Range : British Guiana.

1882, C. M., type, 32 mm. ; 12162, I. U. IM., paratypes, two, 30-32 mm. Kona-
waruk, Middle Essequibo, British Guiana.

Head 4.5; depth 3.33; D. 11; A. 22; scales 4-7 + 23-3. Eye twice as
long as the snout, 2.5 in the head; interorbital a little less than the eye.

Compressed, slender. Head short, compressed, mouth small, oblique; the
maxillary not reaching to below the eye, about two-thirds as long as eye; cheeks
small, entirely covered by the suborbital below, a naked angle below its anterior
margin and a naked border behind it; maxillary margin convex, with three scarcely
perceptible teeth, or none. Anal emarginate; ventrals not reaching anal ; pectorals

^ i<t><>v, a small fish; Sirri with the force of dite in Aphrodite, i. c, born of, descended from.

48 MEMOIRS OF THE CARNEGIE MUSEUM.

not to ventrals. Scales of the back margined with dark; a black median line;
some black at base of ventrals and base of anal.

Genus XII. Macropsobrycon-' gen. nov.

Type : Macropsohrycon iiruguayanoc Eigenmann.

Related to Parecbasis, but having even fainter dentition, and an incomplete
lateral line; related to Aphyodite, but with a naked caudal and a well developed
pseudotympanum; also to Leptobrycon, but with a long anal. It is possible that
some of the species of Megalamphodus should be placed in this genus.

Teeth minute, conical, or but few of them with a lateral notch; six to eight in
the premaxillary, five or six in the front part of the mandible, none on the side of
the lower jaws, none on the maxillary, premaxiUary feeble, maxillary several times
as large, nearly as long as eye, its outer margin very convex, inner margin concave,
not thickened; sides of mandible much raised; adipose fin well-developed; caudal
apparently naked; cheeks entirely covered by the third suborbital; postorbitals
covering about half the width of the postorbital space; frontal fontanel short or
medium; a well marked pseudotympanum.

23. Macropsobrycon uruguayanae, sp. nov. (Plate VI, fig. 2.)

6895a, C. M., type, 46 mm., paratypes 6896a-d, C. M., four, about 45 mm.
Feb. 1, 1909. Haseman.

6897a, C. M., 26 mm. Uruguayana. Haseman.

Head 4.5; depth 3; D. 11; A. 23-25; scales about 30-33, of which about five
are with pores. Eye 3 in head, greater than the very convex interorbital.

Dorsal and ventral profiles both regular, without humps or depressions, the
ventral profile a little more arched than the dorsal; preventral area with about
thirteen scales; predorsal area narrowly rounded with a median series of about
thirteen scales. Occipital process reaching about one-sixth to one-seventh to the
dorsal; frontal fontanel as broad, and less than half as long, as the parietal; the
skull very convex, the third suborbital in contact with lower limb of the pre-
opercle; without a naked angle under its anterior margin, leaving a wide naked
wedge behind its posterior margin; postorbitals narrow and feeble, leaving about
half of the postorbital area naked. GiU-rakers 7 + 15 to 17, very long and slender,
the longest more than one-half the eye.

Premaxillary very feeble, one specimen examined has six slightly graduate
conical teeth, of which only one has a slight notch on one side; another has seven

^ iii-Kpo^is with a long face, i. e., maxillary.

EIGENMAISTN: the CHEIRODONXINiE. 49

teeth, none of which is notched, and still another has either five or six, none notched;
mandibular teeth similar to the maxillar}- teeth and nearly of the same size.

Origin of dorsal very little nearer base of middle caudal rays than tip of snout;
origin of anal under some part of the base of the dorsal, its base longer than head;
ventrals just about reaching anal or not quite to anal; pectorals reach to the
ventrals, which are inserted in advance of the vertical from front of dorsal.

Fig. 13. Macropsohrycon nrugiiayana; Eigenmann. 6896 CM., a, b, c, outlines of premaxillary,
maxillary, and mandible.

Scales have been mostly lost, best preserved in smallest specimen; verj' reg-
ularly arranged, and apparently absent from caudal. Interhsemals of caudal
peduncle few and feeble.

Color uniform, an ovate dark spot on middle caudal peduncle.

This species has the most feeble dentition of any of the members of the
Cheirodontinse; its conical teeth would place it outside this subfamily, but its
relationships are unmistakable.

Genus XIII. Megalamphodus^^ Eigenmann, gen. nov.

Type : Meyalamphodus viegalopterus Eigenmann.

Mouth large, teeth in part notched, in part conical, in a single series, seven to
eleven on the premaxillary, two to twenty on the maxillary; four to eight tricuspid
teeth along front of mandible, minute ones on the sides; all the teeth narrow and
pointed, those of front of mandibles, most of those of premaxillarj^ and usually
the upper ones of the maxillary, each with a minute notch on the sides, the rest
conical; maxillary teeth few or along almost the entire edge; fontanels both very

" /leyaXa/K^os = with spacious ways.

50 MEMOIRS OF THE CARNEGIE MUSEUM.

large, cheeks below the eye entirely covered, the part behind the eye mostly naked.
Form compressed; fins large, origin of anal under dorsal; adipose fin well-developed,
anal truncate or with a narrow lobe; caudal naked; lateral line incomplete; scales
with a few diverging striae.

It is quite possible that the species here included in one genus should be dis-
tributed to other genera. It is certain that the species selected as the type is
generically different from any of the other genera recognized in this paper. As
stated above melanolus may belong to Macropsobrycon, with which the present
genus is very closely related.*

Key to the Species of Megalamphodus.

a. Anal with a narrow lobe, 25-27; depth 2.2-2.4; fourth dorsal reaching caudal; a very conspicuous humeral

bar; dorsal dark, without a distinct spot; about twenty maxillary teeth ... 24. megalopterus Eigenmann.

aa. Anal truncate, the rays graduate; dorsal not falcate in the specimens examined. Maxillary with two to six

teeth.

6. A. 30; depth 2.5; a conspicuous humeral band; most of the dorsal black; anal margined with black.

25. eques Steindachner.

bb. A. 25-28; depth 3.8; premaxillary with about twelve teeth; maxillary with about four teeth, its

length equal to that of the eye; dorsal with a dark spot; a faint humeral spot and a faint caudal spot.

26. melanotus Eigenmann.
bbb. A. 27-30; depth 3; no humeral spot; upper half of the first five developed rays of the dorsal black; six

maxillary teeth. 27. heteresthes Ulrey.

bhhb. A. 24-26; depth 2.4; sides uniformly dusted or with a narrow humeral bar; aU but the first and the
last tluee or four dorsal rays black; caudal and anal margined with black; maxillary with two to six
teeth 28. micropterus Eigenmann.

24. Megalamphodus megalopterus Eigenmann sp. nov. (Plate VII.)
6806, C. M., type, 35 mm. 6807a-b, C. M., paratypes, 3, largest 34 mm.

Caccres, May 23, 1909. Haseman.
Head 3.5; depth 2.2-2.4; D. 11; A. 25-27; lateral line 32-35, 4 to 6 scales
with pores; eye 2.5, slightly greater than interorbital.

Greatly compressed, ventral outline regularly curved; dorsal outline steep
to the dorsal, with a slight depression over the eye, base of dorsal very oblique;
depth of caudal peduncle equal to its length; predorsal area narrow, with a regular
series of nine or ten scales ; preventral area broad, covered with two series of scales
overlapping along the median line with an occasional scale at their angles. Fon-
tanels both very large, anterior end of frontal fontanel equidistant from tip of
snout and its posterior end; parietal fontanel much wider than the frontal; occipital
process extending more than one-fourth to the dorsal. Mouth very oblique,
maxillary as long as eye, reaching to suture between second and third suborbitals;

* For additional species see Appendix to this article.

eigenmann: the cheirodontin^.

51

premaxillary and maxillary teeth of nearly the same size, about eleven on the
premaxillary, about twentj' on the maxillary, anterior mandibulary teeth con-
siderably larger; eight in front and minute ones on the side, third suborbital with
a spur running up behind the e5'e; a wedge-shaped naked area behind it; post-
orbitals obsolete; opercle emarginate above. Gill-rakers 7-1-13, the longest about
equal to the pupil.

Origin of dorsal a little nearer to tip of snout than base of caudal, the fourth
ray highest, reaching to the middle of the caudal in the type; caudal forked, the
lobes longer than head; origin of anal equidistant from base of middle caudal
rays and the origin of the dorsal, below middle of dorsal as measured from tip of

Fig. 14. Megalamphodus melanopterus Eigemuami. 6807, C. M., a, side of head; b, top of head, showing
frontal (/) and occipital (o) fontanels; c, d, e, premaxillan-, maxillary, and mandible, much enlarged. The relay
teeth in the lower jaw are so numerous that they give the impression of a double row.

snout; anal with a narrow anterior lobe equal to length of head, the rays then
of about equal length or decreasing but little to near the end where the fin is
rounded; pectorals reaching bej^ond entire base of ventrals, ventrals to about the
seventh anal ray.

Scales thin with few striae and the rest of the sculpturing verj' weak; caudal
and anal naked, a single series of scales along the base of the anal; pores developed
on a very few scales; eleven scales between ventrals and dorsals.

A very conspicuous, large, humeral bar; dorsal and caudal of varying degrees
of blackness. Anal dusk3^

52 MEMOIRS OF THE CARNEGIE MUSEUM.

25. Megalamphodus eques (Steindachner).
Cheirodon eques Steindachner, Flussf. Siidam., Vol. IV, 1882, p. 37 (Villa Bella;

Obidos); Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891,

p. 54; Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 293; Eigenmann,

Reports Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.

Range: Amazon.

The following is the original description of this species by Steindachner:

"Seitenlinic unvollstiindig, nur 5-8 Schuppen im vorderen Theile des Rumpfes
durchbohrend. Ein querbindenahnlicher, intensiv braunlichschwarzer Fleck in
der Humeralgegend. Ein eben so gefarbter grosser Fleck fast liber die ganze
Dorsalc sich ausbreitcnd. Anale am ganzen unteren Rande briiunlich punktirt,
wie braun gesaumt. Caudalfleck fehlend.

"Die Riickenlinie erhebt sich viel rascher zur Dorsale, als die Bauchlinie sich
bis zur Ventrale senkt, und ist bci grosseren Exemplaren auch etwas starker gebogen
als die Bauchlinie. Hinter der Dorsale senkt sie sich minder rasch als die Bauch-
linie langs der Analflossenbasis ansteigt.

" Die Dorsale beginnt in der Mitte der Korperlange, hinter der Einlenkungstelle
der Ventralen in verticaler Richtung.

"Die grosste Rumpfhohe ist 2j^^mal, die Kopflange 3mal in der Korper-
lange, der Augendiameter 2} 2inal, die Breite der quertiber massig gerundeten Stirne
etwas mehr als 3mal in der Kopflange enthalten und der Schnauzenlange nachste-
hend.

"Der obere Theil des vorderen Oberkieferrandes ist, unter der Loupe betrachtet,
fein gezahnt. Zwischenkieferzahne einreihig.

"Die Spitze der Ventralen reicht liber den Beginn der Anale betrachtlich
hinaus, und die der Pectoralen liberragt gleichfaUs ziemlich bedeutend die Inser-
tionsstelle der Ventralen. Vom 4. oder 5. hochsten Strahle der Anale angefangen
nehmen die folgenden Strahlen nur allmalig an Hohe ab, so dass diese Flosse im
vorderen Theile nach unten keinen lappenformigen Vorsprung zeigt.

"Die Hohe der Dorsale gleicht der Kopflange mit Ausschluss der Schnauze,
die Lange der Ventrale steht der Hohe der Dorsale circa um eine halbe Augenlange
nach.

"Rumpf goldgelb, mit zahllosen violetten Plinktchen libersaet, die jedoch erst
imter der Loupe deutlich unterschieden werden konnen. (P. 38.) Der Humeral-
fleck ist schrag gestellt, nach unten und vorn geneigt stets schmal, doch an Breite
ein wcnig variabel und zuweilen von einer hellen Zone nach vorn und hinten umge-
ben, scharf abgegrenzt und ausnahmslos tief schwarzbraun. Eine gleich intensive

eigenmann: the cheirodontinjE. 53

Farbung zeigt der grosse ninde Fleck auf der Dorsale. Langs der mittleren
horizontalen Schuppenreihe des Rumpfcs liefen bis zum Beginn der Caudale 33
Schuppen.

"D. 11. A. 30. L. lat. 33. L. tr. 6/1/3K-

"Das grosste der von uns untersuchten Exemplare ist 30 mm. lang (mit
EinschJuss der Caudale).

"Fimdort: Amazonenstrom bei Villa Bella imd Obidos."

The lengths of the pectoral and ventrals, the shape of the anal, and the color
make it very probable that eques, which I have not been able to examine in the new
light of these studies, belongs to this genus.

26. Megalamphodus melanotus (Eigenmann).
Aphyocharax melanotus Eigenmann, Mem. Carnegie Mus., Vol. V, 1912, p. 312

(Rockstone on the Essequibo River, British Guiana).

This species is kno\Mi only from the specimens originally described.

1877a, C. M. Type, 43 mm. Rockstone sand-bank. Eigenmann.

Head 4; depth 3.8; D. 10; A. 25; scales 5-33-2, six with pores. Eye 2.75 in
head, interorbital 3.75.

Compressed, preventral and predorsal areas rounded, the latter with a median
series of ten scales.

Frontal fontanel not entirely separating the frontals; second suborbital in
contact with the preopercle below, a very narrow naked area behind it.

Mouth large, the antero-posterior extent of the premaxillary very short; the
maxiUary large, with a curved anterior margin, its length about equal to that of
the eye; about twelve teeth in each premaxillary; maxiUarj' with about four
similar teeth; about twenty teeth on each side of the lower jaw.

Origin of dorsal a little nearer snout than caudal; origin of anal under end of
dorsal; ventrals not quite reaching anal, pectorals not quite to ventrals. Scales
with a few divergent striae. Pseudotympanum faintly evident on one side. Four
chromatophores, tip of anterior dorsal rays dark.

27. Megalamphodus heteresthes (Ulrey).
Aphyocharax heteresthes Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 293

(Brazil); Eigenmann, Report Princeton Univ. Exped. Patagonia, Vol. Ill,

1910, p. 429.

Range: Brazil, definite localities not known.

Head 3.33; depth 3; D. 11; A. 27-30; scales about thirty-one. Eye twice
the length of the snout, 3.5 in the head.

54 MEMOIRS OF THE CARNEGIE MUSEUM.

Maxillarj' teeth six or seven; premaxillary with six to eight conical teeth and
two to four with lateral cusps ; mandible with ten conical teeth and four with lateral
cusps; maxillary extending considerably beyond the anterior margin of the eye.

Origin of dorsal midway between tip of snout and base of caudal. Pectorals

Fig. 15. Megalamphodus hetcresthes (Ulrey), a, top of head, showing frontal (/) and occipital (o) fon-
tanels; b, maxillary; c, premaxillary.

extending beyond tips of the axillary scale; ventrals reaching anal; anal rays
graduate.

No humeral or caudal spots, the upper half of the first developed rays of the
dorsal black.

28. Megalamphodus micropterus sp. nov. (Plate VIII, fig. 1.)

6900a, C. M., t3rpe, 30 mm. 6901a-q, C. M., paratypes, seventeen, largest

about 28 mm. Lagoa do Porto, Dec. 24, 1907. Haseman.
6904a, C. M., paratype, one, 27 mm. Rio Salitre. Haseman.
6902a-i, C. M., paratypes, nine, largest 30 mm. Santa Rita, Jan. 24, 1908.

Haseman.
6903, C. M., paratypes, thirty-five, largest 32 mm. Pirapora, Dec. 14, 1907.

Haseman.
6905a-d, C. M., four in bad state. Boqueirao near mouth of Rio Preto.
This species from the basin of the Rio San Francisco is similar to eques, from
which it differs at least in the number of anal rays.

Head 3.4; depth 2.4-2.75; D. 11; A. 24-26; scales 5 to 7 + 24 to 27. Eye
2.5, much larger than the interorbital.

Similar to M. megalopterus in shape, the back not quite so elevated ; predorsal
area with nine or ten scales.

Mouth large, the maxillary not quite as long as the eye, not reaching to suture
between the second and third suborbitals; premaxillary with seven to nine teeth,
of which one or two may be conical, the rest tricuspid; maxillary with two to six

eigenmann: the cheirodontin^.

55

teeth, of which one or more may be conical; mandible with seven or eight tricuspid
and five to nine conical teeth; occasionally one of the premaxillarj' teeth is placed
a little in front of the line of the others, suggesting Hyphesnobrycon; second sub-
orbital leaving only a narrow naked wedge behind it; postorbitals very feeble.
Gill-rakers 5 + 13.

Origin of dorsal equidistant from tip of snout and base of caudal; dorsal

Fig. 16. Megalamphodus microptenis Eigenmann. a, side of liead; b, top of head, showing frontal (/)
and occipital (o) fontanels; c, d, e, premaxillarj', maxillary, and mandible of a specimen, 6903, C. M., greatly
enlarged;/, outhne of entire mandible; g, portion of a maxillary; h, i, j, k, premaxillaries showing the teeth. In
fig. h there is at a; a tooth out of line, forming an incipient second series.

pointed, its highest rays, second to fourth, not quite equal to the head in length;
caudal lobes not quite equal to the length of the head ; origin of anal under middle
of dorsal; margin of anal truncate, the rays slightly graduate, no lobe, the highest
ray equal to snout and eye; ventrals reaching nearly to, or a little beyond, origin of
anal, pectorals to beyond base of ventrals; males with hooks on the third to six-
teenth anal rays.

Scales thin with a few divergent radial striae; caudal and anal naked.

Sides (in males?) uniformly dusted, or (in females?) with a distinct humeral
band ; all but first and last three or four dorsal rays black; caudal and anal margined
with black; ventrals and pectorals sometimes tipped with dark.

56 MEMOIRS OF THE CARNEGIE MUSEUM.

Genus XIV. Microschemobrycon-^ gen. nov.

Type: Microscliemobrycon guaporensis Eigenmann.

General appearance of Aphyocharax, the lateral line complete to within four
scales of the caudal; three postorbitals, of which the middle one is largest, covering
most of the postorbital area; cheeks covered by the third suborbital; maxillary
slender, the teeth much crowded, and on less than one-third of its length; teeth
narrow, minute, crowded; no pseudotympanum; frontal fontanel moderate; adi-
pose fin moderate; anal base long.

29. Microschemobrycon guaporensis, sp. nov. (Plate VIII, fig. 2.)

6910a, C. M., type, about 37 mm. (30.5 to base of caudal). Maciel, Rio Guapore,
July 23, 1909. Haseman.

Head 4; depth 4; D. 11; A. 22; scales 4-33-3, twenty-nine or thirty scales
with pores; eye 2.75 in the head, snout 3.4, interorbital 3.

About twelve preventral scales, about nine predorsal scales, occipital process
reaching about one-sixth to the dorsal; frontal fontanel not quite 2 in the parietal,
its anterior end a little in front of the middle of the eye; mouth large, maxillary-
premaxillary border 2.75 in the head; maxillary not nearly reaching third sub-
orbital; teeth all minute, those on the mandible conical, with a minute lateral
notch, those on the premaxillary broader; twelve teeth on the premaxillary, twelve
on the maxillary on less than one -third its length; twenty-five or more on the
mandible. Postorbitals in three pieces, the upper and lower ones minute, the
middle one high, less strongly developed than in Aphyocharax.

Gill-rakers 6 + 11, long, 2.5 in the eye.

Origin of dorsal a little nearer snout than base of caudal ; origin of anal under
end of dorsal; ventrals almost reaching anal, pectorals not quite to anal.

Scales well imbricate, firm, without radial striae; caudal and anal naked.

A series of dots from between the ventrals to the base of the anal and along
the root of the anal; some chromatophores on the bases of the caudal rays.

Genus XV. Oligobrycon-'^ gen. nov.

Type : Oligobrycon microstomus Eigenmann.

Teeth heavy, tricuspid, in a single series, very few in number (four on the
premaxillary); the maxillary not reaching anterior margin of orbit; the eight teeth
of the two premaxillaries in a very shallow crescent, maxillary with one to two teeth ;

" juiKpoCTxwoj = small of stature.

^' 6X1705 = small; Brijcon, a genus of fishes.

eigenmann: the cheirodontin^.

57

cheeks with a very narrow naked margin; three postorbitals; lateral line incom-
plete; scales with few divergent radial stria?; caudal naked; adipose well-developed.
Interhsemals not evident; no pseudotjTnpanum.

This genus differs from Aphyocharax and from Mixobrycon ribeiroi in dentition,
the size of the mouth, the armature of the cheeks, etc.

30. Oligobrycon microstomus sp. nov. (Plate IX, fig. 1.)
6898a, C. M., type, 39 mm.; 6899a, C. M., paratype, 27 mm. Jacarehy, Rio

Parahyba, July 15, 1908. Haseman.
Very similar in shape, size of mouth, and general appearance to Cheirodon
interruptus.

Head 3.5; depth 2.3-2.6; D. 11; A. 24 or 25; scales 7 or 8 + 25, twelve scales

Fig. 17. Oligobrycon microstomus EigenmsLvm. 6699, C. M. a, outlineof top of head; 6, c, rf, premaxil-
lary, maxillarj', and mandible enlarged; e, dentition of specimen 6898, C. M.;/, suborbitals and postorbitals of
6699, CM.

between dorsal and vcntrals ; eye three times in the head, a little less than intcrorbital ;
caudal peduncle as deep as long; base of anal a little longer than head.

Very deep and compressed; dorsal and ventral profiles nearly equally arched;
proven tral area rounded, without a definite median series of scales; predorsal area
with a blunt keel; about eight scales in a median series from the dorsal forward

58 MEMOIRS OF THE CARNEGIE MUSEUM.

and three overlapping rows of scales between these and the occipital process;
occipital process extending about one-fifth to dorsal, bordered by tliree scales;
frontal fontanel long, pointed, about one-half as long as the parietal with its groove;
interorbital nearly flat, very broad; snout blunt, face of maxillary nearly vertical;
margin of second suborbital convex, leaving a narrow naked margin of nearly
equal width around its entire margin; postorbitals strong, leaving a narrow naked
margin; mouth minute; maxillary verj^ broad and short, not reaching to below eye,
a little more than half as long as eye; maxillary-premaxillary border about three-
fourths as long as eye. IVIaxillary with one or two minute teeth; premaxillary
wnth four graduate teeth; mandible with six graduate teeth. Gill-rakers 5 + 8,
short.

Origin of dorsal equidistant from tip of snout and base of caudal or a little
nearer the latter, its height equal to length of head to upper angle of gill-opening;
origin of anal under middle or behind middle of dorsal; ventrals just reaching anal;
pectorals reaching to ventrals.

Scales very regularly imbricate, those of the belly with many sub-parallel
radial strise, those of the sides with divergent stride.

A vertical humeral bar crossing the third and fourth scales of the lateral line;
an oval spot on the end of the caudal pedvmcle; region between nape, dorsal, and
anal nearly evenly peppered; region forward of a line joining base of ventrals
and the humeral spot silvery.

Genus XV. Aphyocheirodon^'' gen. nov.

Type : Aphyocheirodon hemigrammus Eigenmann.

Teeth notched, in a single series, those in the maxillary and premaxillary
narrow, with nearly parallel edges, and with three or five cusps, the median one
prominent, the lateral ones small; premaxillary teeth about eight to ten in number;
maxillary teeth four or five on the upper fourth of the edge of the maxillary. ]\Iandi-
bulary teeth much expanded at tip, the margins of neighboring teeth in contact, the
tip chisel-shaped, divided into three lobes of equal size, a minute cusp on each side.
Mouth large; cheeks partly naked; frontal fontanel very short; adipose fin well
developed; caudal naked; lateral line incomplete; scales ^\'ith a few diverging radial
strise; no pseudotjinpanum.

It is very probable that there is but little difference between the sexes, the
caudal fulcra being normal. Only one species is thus far knowTi.

" iipOri = a small fish ; Cheirodon, a genus of this subfamily of fishes.

eigenmann: the cheirodontin^.

59

31. Aphyocheirodon hemigrammus sp. nov. (Plate IX, fig. 2.)
6802, C. M., type, 45 mm. 6803, C. M., paratypes, twenty -six, largest 48 mm.

Jaquara, Aug. 18, 1908. Haseman.
6804a-d, C. M., paratypes, four; largest 45 mm., Mogy Guassu, Aug. 25, 1908.

Haseman.
6805a, C. M., paratype, one, 39 mm. Riberao Azul, 12 miles from Tiete, Oct. 7,

1908. Haseman.
Range : Tiete basin, Jaquara.

Head 4; depth about 3; D. 11 rarely 10; A. 23-25 (27 in one); scales usually
34, more rarely 36 or 37; eye 2.5-3 in the head, about equal to the interorbital.

oxen

Fig. 18. Aphyocheirodon hemigrammus Eigenmann. a, outline of head; 6, c, variations in the post-
orbitals; d, top of head, to show form and location of the fontanels; e, premaxillary;/, maxillary; g, mandible,
showing relay teeth at r and p; h, outline of entire mandible, showing teeth-bearing portion at x. (All figures
much enlarged.)

Compressed, elongate, dorsal and ventral profiles nearly equally arched; pre-
ventral area rounded; sometimes a nearly regular median series of twelve scales,
sometimes the scales irregular; postventral area rounded; predorsal area roinidod,
with a median series of about twelve scales; occipital process bordered by two or
three scales reaching one-seventh to the dorsal; skull convex above; frontal fon-
tanel very small, the frontals sometimes mesially in contact with the bridge;

60 MEMOIRS OF THE CARNEGIE MUSEUM.

parietal fontanel very large; mouth large, the maxillary equal to the eye, not quite
reaching the suture between the second and third suborbitals. Third suborbital
leaving a naked area around its entire convex free margin; a naked area about
half as wide as the postorbital behind the postorbitals. The postorbitals in two
or three parts, very variable. Gill-rakers 4 + 10, longest about half the length
of the eye.

Premaxillary teeth eight to ten, of nearly uniform size, their margins sub-
parallel, the median cusp more prominent than the lateral; maxillary teeth similar,
but smaller than the premaxillary teeth, and with three cusps. Mandibulary
teeth graduated on the side of the jaw, the anterior six or seven of about equal size,
their tips broad, the bases narrowed, the three median points alike, forming a con-
tinuous cutting edge, the expanded tips of the teeth being in contact, a minute
cusp on each side.

Origin of dorsal equidistant from tip of snout and end of middle series of scales,
the dorsal pointed, its height about equal to the length of the head; adipose fin
well developed; caudal lobes about equal to length of the head; origin of anal
below middle or posterior part of dorsal, its margin distinctly emarginate, the
height of the lobe less than the length of the head; ventrals reaching anal; pectorals
reaching ventrals.

Scales with a varying number of radiating strise, everywhere regularly imbri-
cate; caudal naked; no distinct row of scales along the base of the anal; axiUary
scale very small; eight to ten scales with pores; ten scales between dorsal and
ventrals.

A conspicuous black spot occupies the entire width of the caudal peduncle and
half the length of the middle caudal rays. A median dusky line associated with a
narrow silvery line on posterior half of body. No other markings.

Male scarcely distinguishable from the female, lower caudal fulcra not modified.

Genus XVI. Compsura^' gen. nov.

Type : Compsura heterura Eigenmann.

Closely allied to Cheirodon, but differing much in the structure of the male.

Teeth few; multicuspid incisors in a single series; mouth minute; second sub-
orbital in contact with the preopercle below and partly behind; postorbital leaving
a naked area behind about half as wide as the bone; adipose fin well -developed;
caudal fulcra in both sexes covered by scales; a lobe of large scales in the male
extending along the base of the middle caudal rays; lateral line incomplete; scales

^' KofitpSs = well dressed; 6vpa = tail.

eigenmann: the cheirodontin^.

61

with a few diverging striae. All but the three or four last of the divided anal rays
of the male with hooks.

32. Compsura heterura sp. nov. (Plate X, fig. 1.)
6808, C. M., type cf, 36 mm. 6809a-k, C. ^L. paratypes, five males and eight

females, largest 37 nun. Queimadas, Rio Itapicurii, ^larch 2, 1908. Hase-

man.
6810a, C. M., cf , 31 mm. Barreiras, Lagoaof Rio Grande of Rio San Francisco,

Jan. 3 and 4, 1907. Haseman.
6811a-c, C. M., cf , 32 nam. Santa Rita, Jan. 24, 1908. Haseman.
Range : Rio San Francisco and Rio Itapicuru.
This species with the general appearance of a Cheirodon can readily be dis-

FiG. 19. Compsura helerura Eigenmann. a, outline of side of head; b, top of head, showing frontal
(/) and parietal, or occipital (o) fontanels; c, c', right and left preiuaxillaries; d, maxillary, e, mandible of an
individual, 6809, C. M., greatly enlarged; /, premaxillary of another individual; g, scaling of the tail of a male,
6808, C. M. (All figures greatly enlarged.)

tinguished by the black upper half of the first dorsal membrane together with the
black tip of the dorsal.

62 MEMOIRS OF THE CARNEGIE MUSEUM.

Head 4-4.25; depth 2.5-2.75; D. 10 or 11; A. most frequently 19, ranging
from 17-20; scales 34-35, rarely 32, eight or nine scales with pores, ten scales
between dorsal and ventral; eye 2.6-3 in head, about equal to the interorbital ;
depth of caudal peduncle about equal to its length.

Compressed, dorsal and ventral outlines evenly and equally curved. Pre-
ventral area rounded with a median series of eleven scales; predorsal area rounded
with a median scries of nine scales, extending to within two scales of the occipital
process; occipital process broad and short, reaching about one-seventh to the dorsal,
bordered bj' two and one-half scales on each side; skull convex, frontal fontanel
only about one-fourth as long as the parietal; mouth very short and small, maxillary
very little, if any, more than half as long as the eye; teeth broad-tipped, five- or
seven-pointed, median point largest, projecting; four teeth on the premaxillary,
two on the maxillary, eight or nine on the mandible, those on the side of the man-
dible graduate, the last one may be minute and single pointed, all the rest of the
teeth similar in size and shape; third suborbital strong, in contact with the pre-
opercle below and partly behind; postorbitals thin, ill defined, leaving a considerable
naked area. Gill-rakers 4 + 8, very short, only about one-fifth as long as eye.

Origin of dorsal a little nearer tip of snout than base of caudal, the fin pointed,
the highest ray about equal to the head; adipose fin small; caudal forked, the
lobes about equal to the length of the head; origin of anal behind the vertical
from the last dorsal ray; anal fin but slightly emarginate, its base Httle shorter
than the head; all but the last three or four of the divided anal rays of the male
with seven or eight strong recurved hooks. Pectorals of the male reaching the
ventrals; ventrals of the male truncate, reaching the anal, ventrals of the female
pointed, not reaching the anal; the pectorals in the female not reaching the ventrals.

Scales thin, regularlj^ imbricate, very few diverging striae; anal with about
three scales forming a sheath at the base of the anal; base of caudal in the male
scaled, the scales covering the caudal fulcra and forming a lobe along the middle
of the fin.

Tip of dorsal and upper part of membrane between the rudimentary and first
full ray black; tip of anal in the male black; a conspicuous triangular caudal spot
not quite extending to the end of the middle rays ; a black band extending forward
to below the dorsal.

Genus XVIII. Mixobrycon -^ gen. nov.

Type : Mixobrycon ribeiroi (Eigenmann) .

Closely resembling Hyphessobrycon; teeth heavy, few, in a single series; third

2' /iijis = a mixing; Brycon, a genus of Characins. Name chosen because the teeth show some of the
characters of Hyphessobrycon.

eigenmann: the cheirodontin^.

63

suborbital with a wide naked area around its entire border. Postorbital covering
nearly the entire postorbital space. Mouth moderate, the maxillary not reaching
to the end of the second suborbital; adipose fin well developed; caudal naked;
lateral line short; frontal fontanel large, entirely separating the frontals; no pseudo-
tympanum; no prominent interhaemals.

33. Mixobrycon ribeiroi (Eigenmann). (Plate X, fig. 2.)
Cheirodon ribeiroi Eigenmann, Proc. U. S. Nat. Mus., Vol. XXXIII, 1907, p. 9;

Reports Princeton Univ. Exp. Patagonia, Vol. Ill, 1910, p. 429.

10229, 1. U. M., one, type, 35 mm. to base of caudal. Puerto Max, Paraguay,
J. D. Anisits.

This species is known only from the tjrpe.

Head 3.4; depth 3; D. 11; A. 26; scales 5-33-4, seven scales with pores.
Eye 2.5 in the head, greater than interorbital.

Compressed, elongate; preventral area rounded; predorsal area rounded, with
a median series of eleven scales; occipital process elongate, pointed, reaching one-

FiG. 20. Dentition of Mixobrycon ribeiroi Eigenmann.

fifth to dorsal, bordered by three scales on each side; frontal fontanel long, pointed,
1.5 in the parietal; maxiUary long, slender, nearly three-fourths as long as eye;
premaxillary with four large, heavj^ teeth; the second tooth largest, with seven
points, the middle point of which is the largest, the base of the tooth much nar-
rower than the tip; the second to fourth teeth graduate; no teeth on the maxillary;
mandible with four, heavy, five-pointed, graduate teeth; teeth of side of jaw lost
or absent; second suborbital with a wide naked area around its entire margin.
Gill-rakers 7 + 11, the longest about one-third as long as eye.

Origin of dorsal very nearly equidistant from tip of snout and caudal; origin
of anal under back part of dorsal; onlj^ one interha^mal (or none?) on the caudal
peduncle; pectorals reaching ventrals, the latter not to anal; adipose fin well-
developed.

64 MEMOIRS OF THE CARNEGIE MUSEUM.

A large humoral spot over third to fifth scales of lateral line; a dark line from
upper part of humeral spot to middle of caudal; caudal spot extending across the
entire caudal peduncle, and on middle caudal rays.

Named in honor of Dr. Alipio de Miranda Ribeiro of Rio de Janeiro.

Genus XIX. Cheirodon^" Girard.
Cheirodon Girard, Proc. Acad. Nat. Sci. Phila., Vol. VII, 1854, p. 199.

Type : Cheirodon pisciculus Girard.

Minute fishes ranging from 25 to 60 mm. in length; teeth of the upper and
lower jaws similar, with five or more points; usually the tips of the teeth are
expanded, more rarely the margins of the teeth are nearly parallel, arranged in a
single series; one to three teeth on the maxillary, four to nine teeth on the premaxil-
lary (most frequently five) ; cheeks usuallj^ nearly completely covered by the third
suborbital, but with a naked area around its entire border in C. amice; the origin
of the dorsal very nearly equidistant from tip of snout and base of middle caudal
rays; adipose fin well-developed; origin of anal about under the last dorsal ray; a
variable number of the anal rays and sometimes the ventral rays in the males with
numerous hooks, the base of the hook-bearing portion of the anal not infrequently
at an angle with the base of the normal portion; interhsemal spines of the caudal
peduncle variable, those of the male strong, protruding, sometimes ankylosed and
sometimes with broad wing-like lateral processes. Scales thin, regularly imbricate,
with a variable number of radial strise. Caudal naked, anal with a few scales in a
single series at the base of the anterior rays; scales moderate, between thirty to
thirty-six in the lateral series, of which not more than twelve have pores. No
humeral spot, the covering of the anterior air-bladder very thin, in a triangular
pseudotjonpanum ; usually a conspicuous caudal spot, more rarely a dorsal spot.

Range: Amazons, Panama, eastern slope of Colombia, south to the Rio
San Francisco, Rio Parahyba, Rio Grande do Sul, and the La Plata basin; western
slope of Chili.

No specimens of Cheirodon jnsciculus are at hand. It is possible that the
specimens of Cheirodon annce, listed below, the origin of which is unknown, are in
reality the types of Cheirodon pisciculus. If so, then the species listed after C
annce are representatives of a genus distinct from Cheirodon. If, however, Cheirodon
pisciculus is distinct from C. anna; and agrees with the species which here succeed
it, then C. annce should be made the type of a distinct genus. C. annce certainly is
not congeneric with the other species of Cheirodon here figured. C. microdon and

2" x«'p, i = hand; o&6it>, 6 = tooth.

eigenmann: the cheirodontin^. 65

C. stenodon are also quite distinct from the rest of the species. This is the only
genus of Characins reaching the Pacific slope of ChiU, where at Puerto Alontt it
also attains the southernmost latitude recorded for the Characins.

Key to the Species of Cheirodon.
a. A naked area about the entire distal margin of the tliird suborbital, very wide beliind it; elongate, depth 3 or
more in the length; mouth moderate; teeth broad-tipped with narrow bases; anal short, 12-15, the
tip of the first developed ray extending beyond the tip of the last; caudal peduncle slender, about
twice as long as deep. (Not examined in C. piscicvlus.)

b. Maxillary with two teeth [34. pisciculus Girard.

66. Maxillary with one tooth 35. annae McAtee.

aa. Second suborbital in contact with the preopercle at least below; anal emarginate 17-27.

c. Mouth minute or moderate; teeth broad-tipped.

d. Fifteen to twenty interhaemals," ex-tending from near base of last anal ray to caudal, with broad,
wing-like lateral processes in the male; a naked area along the entire posterior edge of the
tliird suborbital.
e. Three, more rarely two, maxillary teeth; maxillary very httle more than half the length of
the eye, its margin straight; premaxillary with five teeth; A. 18-19; eighteen to twenty-
three interhffimals from near base or beliind tip of last anal to caudal; base of anal equals

length of caudal peduncle; largest about 25 mm 36. insignis Steindachner.

ee. Two maxillary teeth; maxillary about half the length of the eye, its margin but little eur^-ed;
prema.xillary with four teeth; A. 19-24; fifteen to twenty interhtemals, ex-tending from near
base of last anal ray to caudal; base of anal much longer than caudal peduncle. Length of

largest recorded specimen 39 mm 37. parahybae Eigenmann.

eee. One maxillary tooth; maxillary about half the length of the eye, its margin strongly convex;
premaxiUary with four or five teeth; A. 17-24; twenty or more interhsemals; extending from
near base of last anal ray to caudal. Largest recorded specimen, 60 mm.

38. interruptus Jenyns.

39. monodon Cope.

40. ibicuhiensis Eigenmann.
dd. Eight to thirteen interhtemals extending from near tip of last anal ray to caudal ; base of anal equals

caudal peduncle and middle caudal rays; maxillary scarcely reaching eye; cheek.s with a
naked wedge behind the second suborbital.
/. Dorsal with black spot along the base of the anterior rays; A. 20-22; scales 32-34; premaxillary
with four teeth, maxillary with two; a spot across the entire caudal peduncle.

41. notomelas Eigenmann.
ff. Dorsal without a distinct black spot.

g. No caudal spot or other definite markings; premaxillary with five teeth; maxillary with

two; about nine weak interhsemals. A. 23; scales 36 42. madeirs Eigenmann.

gg. A large conspicuous caudal spot sometimes continued to the end of the middle rays.
h. Anal plain; scales 31-36; premaxillary with four or five teeth, maxillary usually with
two; nine to thirteen interhsemals, occupying half the distance between the anal

and caudal; A. 19-27 43. piaba Lutken.

cc. Mouth moderate; teeth in premaxillary narrow, five to nine in number; maxillary teeth two-tliirds to
" See also insignis, in which there may be only eight.

66 MEMOIRS OF THE CARNEGIE MUSEUM.

three-fourths as long as eye; dorsal with some black; depth 2.8-3; interhsemals of caudal peduncle
feeble; third suborbital leaving only a naked wedge behind it.
i. Three median points of teeth of mandible equal in size; seven to nine teeth in premaxillary; depth
2.8; A. 23-35; maxillary three-fourths as long as eye; seven to nine teeth in premaxillary, two in

maxillary. Scales 34-36 44. microdon Eigenmann.

ii. Teeth of lower jaw similar to those of upper, but a httlc wider, one large median point and two small
points on each side; five to seven teeth in'premaxillarj^ two teeth in maxillary; depth 3; A. 18-
22; maxillary two-tliirds in eye; scales thirty-six or thirty-seven. .. .4.5. stenodon Eigenmann.

34. Cheirodon pisciculus Girard. (Plate XVII, fig. 4.)
Cheirodon pisciculus Girard, Proc. Acad. Nat. Sci. Phila., 1854, p. 199; U. S. Nav.

Astronom. Exped., Fishes, 1855, p. 249, pi. 34, figs. 4 and 7 (Santiago, Chili);

Eigenmann and Eigenmann, U. S. Nat. Mus., Vol. XIV, 1891, p. 54; Ulrey,

Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 290; Eigenmann, Reports Princeton

Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.
Chirodon piscicidus Glinther, Cat. Fish. Brit. Mus., Vol. V, 1864, p. 332; Stein-

dachner, Zool. Jahrbuch., Suppl. IV, 1898, p. 328 (Llanquihue, near Puerto

Montt, Chih).

Range: Southern Chih.

I have seen no specimens of this species. The following is an abridgment of
Girard's description:

Head 4; depth 3-4; D. 10; A. 14. Eye 3 in the length of the head; depth of
caudal peduncle 2.5 in the greatest depth.

Snout short and rounded; eye rather large. Maxillary teeth very small and
few. Dorsal fin higher than long. Caudal forked. Anal nearly as deep as long.
Ventrals and pectorals slender. Scales proportionately verj- large, higher than
long. A silvery band along the middle of the flanks, margined above with black.
Fins unicolor, olivaceous.

A small fish of a rather short appearance, in spite of the slenderness of the
peduncle of the tail. Dorsal and ventral lines equally arched. Body very much
compressed; mouth small and slightly oblique; maxillary extending to a vertical
line immediately in advance of the anterior rim of eye when the mouth is closed.
Dentary teeth much larger than those on the intermaxillaries. Their form is
flattened, dilated towards their upper edges, which are provided generally with
five subconical points, the middle one being the longest, giving them the appearance
of digits.

Origin of dorsal nearer base of caudal than tip of snout; dorsal much higher
than long, its upper edge roimded or subconvex. The adipose is slender, nearer
to the base of the caudal than to the posterior edge of the dorsal and consequently

eigenmann: the cheirodontin^. 67

situated behind the anal. The anal longer than the dorsal, and nearly as long as
deep; its exterior edge convex anteriorly, and subconvex posteriorly. Its anterior
margin is situated backwards of the posterior edge of the dorsal.

The caudal fin, which constitutes about one-fifth of the total length, is deeply
forked posteriorly; its lobes are rather round and onlj' acute at their extremities.
The insertion of the ventrals is on the middle of the abdomen, somewhat in advance
of the anterior margin of the dorsal. These fins are rather slender, with their tips
acute and reaching the vent. The origin of the pectorals is situated near the
inferior region of the thoracic belt. These fins are longer and slenderer than the
ventrals, their tips almost reaching the origin of the latter fins. Their anterior ray
is simple; the central rays are but once bifurcated, and only towards the last third
of their length.

The scales are of moderate development, higher than long, subelliptical in
shape, sometimes very irregularly so. Ten or eleven longitudintal rows on the
line of the greatest depth, and six or seven rows on the peduncle of the tail. The
lateral line is not to be seen.

Olivaceous brown; a silver band along the middle of the flanks, extending
from the upper angle of the opercular apparatus to the base of the caudal fin. The
cheeks, the opercles, and branchiostegal apparatus are silvery. A blackish stripe
along the upper edge of the silvery band of the sides. The dorsal region is minutely
dotted with blackish, the dots being more particularly crowded upon the outline
of the scales. These dots extend to the upper surface of the head, and sparingly
to the upper region of the thoracic and abdominal regions; also to the inferior
half of the peduncle of the tail. The dorsal, caudal, and anal fins are almost greyish
through the accumulation of the above-mentioned dots. The ventrals are unicolor;
the pectorals greyish upon their external margin. The abdominal region sometimes
exhibits an argentine reflection.

Inhabits the lagoons in the vicinity of Santiago, Chile.

35. Cheirodon annae McAfee. (Plate XI, fig. 1.)
Cheirodon annw McAfee, Proc. Acad. Nat. Sci. Phila., 1903, p. 515 (South America);

Eigenmann, Reports Princeton Univ. Patagonia, Vol. Ill, 1910, p. 429.

Habitat : Some unknown locality in South America.

The specimens of this species were received as an exchange from the U. S.
National Museum. Their origin is in doubt. It is possible that they are the types
of C. pisciculus.

68

MEMOIRS OF THE CARNEGIE MUSEUM.

4301, I. U. M. 927a-b, C. M. Type and paratypes, fifteen. Length of type,
43 mm. South America.

The specimens are soft and have lost their scales. The characters are other-
wise well-preserved. If these specimens came from Chile, there is no doubt that
thej^ represent C. pisciculus, with which they agree in their extremely short anal
and their elongate form.

Head 4.2; depth 3.6-4.2; D. 9-12; A. 12-15; scales 32-36, eleven scales
between ventrals and dorsal, seven to nine scales with pores; eye 2.8-3.2; depth of
caudal peduncle about 2 in its length.

Elongate, little compressed; predorsal and preventral areas rounded, with
about (?) fifteen scales; occipital process short, reaching one-eighth to the dorsal;

Fig. 21. Cheirodon anrue McAtee, a, maxillary; 6, premaxillary; c, portion of mandible; d, dentition
seen from in front. 4307, C. M.

frontal fontanel half as long as the parietal; third suborbital very small, leaving a
naked area, which is much the widest behind, about its entire distal margin;
postorbitals minute, not covering more than one-fourth of the width of the cheek
behind the eye; snout blunt, mouth small, maxillary a little over half as long as eye;
teeth five- to seven-pointed, the middle point a little prominent, the bases of the
teeth much contracted; four or five teeth in the premaxillary, one tooth (absent in
two)' on the maxillary, mandible with five or six graduated teeth. Gill-rakers
8 -h 12, short, about one-third as long as eye.

eigenmann: the cheirodontin^.

69

Origin of dorsal a little nearer caudal than tip of snout, its height a little less
than the length of head; adipose fin well-developed; caudal lobes about as long
as head; base of anal about equal to snout and eye, considerably less than the length
of the caudal peduncle; origin of anal below, or a little behind, the base of the
last dorsal rays, first developed ray of the anal extending beyond the tip of the

fifttWirA- Fig- 22
Fig. 23
the interhsemals of cf .

Cheirodon annw McAtee.

Cheirodon jmmfs IVJcAtee.

Interhaemal spines of cf .

a, premaxillary; 6, maxillary; c, portion of mandible; d, portion of

last ray; ventrals extending to, or a little short of, origin of anal, pectorals to, or a
little short of, ventrals.

Thirteen interhsemals on the caudal peduncle of the female, extending four-
tenths to base of last anal ray. The spines very strong, with broad lateral processes
in the male, extending a little further toward the anal. Scales mostly removed. A
distinctly silvery lateral band.

36. Cheirodon insignis Steindachner. (Plate XVII, fig. 2.)
Cheirodon insignis Steindachner, Fisch-Fauna Cauca & Fliisse bei Guayaquil, 1880,

p. 22, pi. VI, fig. 3 (Cauca); Eigenmann and Eigenmann, Proc. U. S. Nat.

Mus., Vol. XIV, 1891, p. 54; Eigenmann, Reports Princeton Univ. Exped.

Patagonia, Vol. Ill, 1910, p. 429; Evermann & Goldsborough, Proc. Biol.

Soc. Washington, Vol. XXII, p. 98 (Tabernilla, Atlantic slope of Panama

Canal Zone).
Cheirodon gorgonce Evermann & Goldsborough, I. c. p. 99. Below the dam at Gorgona,

Canal Zone.*-

^ This species is said to differ from insignis " in the larger eye, the fewer anal rays and the slightly shorter
dorsal rays" as well as in the teeth. The differences found may be tabulated as shown at foot of p. 70:

Meek & Hildobrand reporting on the wealth of material collected by them
in Panama (Field AIus. Publ. Zool. Ser., vol. X, 1916, pp. 273-276), find that
the specimens reported as Cheirodon insignis by Evermann and Goldsborough
are representatives of a new genus and species, Pseudocheirodott affinis,
Meek & Hildebrand, and that Cheirodon gorgonae Evermann & Goldsborough,
placed in the synonymy of Cheirodon insignis, is a member of the genus Comp-
sura.

70 MEMOIRS OF THE CARNEGIE MUSEUM.

Range : Magdalona and Atrato basin, Atlantic slope of Panama.

5367, C. j\I., 13042, 1. U. M., many, largest about 25 mm. Tniando. Wilson.
726, University of Michigan Museum, two, largest about 28 mm. Marsh at
Fundacion, Colombia.

Head 4; depth 2.5-3; D. 10 or 11; A. 17-20; scales 28-32, of which about
six have pores; eye 3 in head, about equal to interorbital.

Compressed, breast slightly flattened, with a median series of nine or ten
scales; predorsal area with about nine scales; occipital process short, reaching
about one-sixth to the dorsal; frontal fontanel an equilateral triangle less than one-
half as long as the parietal fontanel without the groove; maxillarj'- reaching to below
anterior margin of eye; third suborbital covering the entire cheek; premaxillary
with five teeth; maxillary with two or three teeth.

Dorsal falcate, sometimes reaching to adipose, its origin in middle of body;
anal emarginate, its lobe in the male reaching tip of last ray, not quite tip of last
ray in female; ventrals reaching bej'ond origin of anal in male, the pectorals to the
middle third of the ventrals; both fins shorter in the female.

Scales regularly imbricate, largest just above pectorals and ventrals; caudal
naked; anal with a single series of scales along its base; ten scales between dorsal
and ventrals.

Interhsemals extending from near base or tip of last anal ray to caudal, eight to
twenty-three in number, those of the males antrorse and with lateral wings, those
of the female slender, their tips not exposed, pointing do\Miward and backward.

A conspicuous caudal spot, surrounded by an unpigmented area; back and
sides nearly uniformly punctate; margin of anal and dorsal dark.

37. Cheirodon parahybae sp. nov. (Plate XI, fig. 2.)
6841a, C. M., type, 38 mm. 6841b-f, C. M., paratypes, six, largest 39 mm.

Campos, June 14, 1908. Haseman.
Head 3.75-4; depth 2.5-2.7; D. usually 11, rarely 10; A. 19-24; scales 34-36,
eight or nine with pores; ej^e 2.5 in the head.

Compressed, preventral area and predorsal areas rounded, the somewhat

C. insignis C. gorgonw

Head 3.6-3.8 3.5-3.8

Depth 2.8-3 3-3.2

Eye in the head 2..5-2.6 2.2-2.4.5

Longest dorsal ray in head 8 1

Anal 21-22 17-19

Longest anal ray in head 1.4-1.8 1.4-1.6

eigenmann: the cheirodontin^. 71

irregular median series consisting of about eleven scales; occipital process short,
extending one-seventh to dorsal, bordered b}' three scales on each side; frontal
fontanel half as long as the parietal; second suborbital in contact with the pre-
opercle below, a broad naked area along its entire posterior margin; postorbitals
feeble, not covering more than half the width of the postorbital area; maxillary
little, if any, more than half as long as eye, slender, its margin not curved; teeth
small, slender, contracted at the base, with five points, the middle one being largest;
four teeth in the premaxillary, two in the maxillary, seven or eight graduated teeth
on the mandible. Gill-rakers about 7 -\- 10, very short, not quite one-fourth as
long as eye.

Origin of dorsal a little nearer tip of snout than base of middle caudal rays or
the reverse. Dorsal pointed, its height equal to the length of the head, or a little
longer; adipose fin well-developed; caudal lobes much longer than head; origin of
anal below the posterior part of the dorsal or behind the vertical from the last ray;
fifteen to twenty interha^mal spines, extending from near base of last anal ray to
caudal, with broad wings in the male; ventrals about reaching anal, pectorals a
little bej'ond origin of ventrals. Scales thin, regularly imbricate, with few radial
striae; caudal naked, anal with a few scales on the bases of the anterior rays.

A large spot extending across the entire caudal peduncle, not extending on
the middle caudal rays.

This species is very similar to C. piaba and C. interruptus, differing in the size
of the naked area of the cheek, the number of interhsemal spines, the length of the
maxillary, and the number of maxillary teeth.

38. Cheirodon interruptus (Jenyns). (Plate XII, fig. 1.)

Tetragonopterus interruptus Jenyns, Voy. Beagle: Fishes, 1842, p. 127, tab. 23,
fig. 4 (Maldonado).

Chirodon interruptus Giinther, Cat. Fishes Brit. Mus., Vol. V, 1864, p. 332; Perugia,
Ann. Mus. Civ. Storia Nat. Genova, (2), Vol. X, p. 45, 1891 (Rio Plata).

Cheirodon interruptus Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV,
1891, p. 54; Uh-ey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 290; ? Boulenger,
Boll. Mus. Univ. Torino, Vol. XII, 1897 (Tala); Eigenmann, Reports Prince-
ton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.

Cheirodon monodon Cope, Proc. Am. Philos. Soc, Vol. XXXIII, 1894, p. 91 (Rio
Grande do Sul); Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 290; Fowler,
Proc. Acad. Nat. Sci. Phila., 1906, p. 332 (Rio Grande do Sul); Eigenmann
& Ogle, Proc. U. S. Nat. Mus., Vol. XXXIII, p. 9 (Rio Grande do Sul).

72 MEMOIRS OF THE CARNEGIE MUSEUM.

Eigcnmann, Reports Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.

Range : INIaldonado to Rio Grande do Sul.

The types of interruptus came from Maldonado and the specimens collected
bj' Carey at the same place (No. 20698, M. C. Z.) are more than probably inter-
ruptus. These specimens are specifically distinct from the Paraguayan specimens,
heretofore referred to C. interruptus. A careful comparison with the excellent
fresh specimens from the Paraguay river and others from various places in the
San Francisco basin, collected by Haseman, shows that they are so similar, that
the Paraguaj'^an form hitherto referred to interruptus must be referred to C. piaba.

Fig. 24. Interhaemals in Cheirodon interruptus Jenyns. 6818, C. M.

Specimens from Rio Grande do Sul, the type locality of C. monodon, are very

similar to C. interrupttis, and monodon may be considered a variety of interruptus.

6815a-k, C. M., two males, eleven females, largest 45 mm. Rio Guahyba,

Porto Alegre, Rio Grande do Sul. Jan. 21, 1909. Haseman.
6817a-d, C. AL, fourteen, largest 40 mm. Santa Maria, Rio Vaccacahy-

Mirim, secondary tributary of the Rio Jacuhy, Rio Grande do Sul. Hase-
man.
6818a-x, C. M., three males, largest 43 mm., twenty-six females, largest 49 mm.

Cachoeira, Rio Jacuhy, Rio Grande do Sul. Jan. 26, 1909. Haseman.
6852a, C. M., one female, 47 mm. Cacequy. Haseman.
846 & 847, M. C. Z., twelve, poor, largest a male about 35 mm. long. Uruguay

river. Wyman.
20698, M. C. Z., forty, largest about 60 mm. and 20699, M. C. Z., one, 46 mm.

Alaldonado. T. G. Carey.
6816a-j, C. M., one male, 42 mm., nine females, largest 52 mm. Cacequj^, Rio

Ibicuhy, into Rio Uruguay. Jan. 31 & Feb. 1, 1909. Haseman.
This species can readily be distinguished by the naked area behind the third
suborbital and by the numerous interhaemals. They extend from the anal to the

eigenmann: the cheirodontin^. 73

caudal and number seventeen to twenty-seven, all or only half of which maj' pro-
trude in the male. The maxillary has but one tooth.

Head 4.5-4.66; depth 2.4-3; D. 11, very rarely 12; A. 17-24; scales ^, ¥,
TT, 7-,^, in those examined; seven to twelve scales with pores; eye 2.5-3, about
equal to interorbital ; depth of caudal peduncle 1-1.5 in its length.

Compressed, dorsal and ventral profiles equally arched; preventral area
flattened, with a median series of about thirteen scales; predorsal area rounded,
with thirteen scales; frontal fontanel from half to one-third as long as the parietal;
a broad naked area behind the third suborbital, sometimes extending forward a
little at the angle of the preopercle, postorbital not half as wide as the naked
area behind it; mouth small, maxillary little, if any, longer than half the eye,
shortest in specimens from Cacequy and Maldonado, in which its free margin is
more convex. Premaxillary with four or five teeth (six in a few premaxillaries) ;
maxillary uniformly with a single tooth (except in one maxillary, which in addition
has a minute tooth); five, six, or seven graduate teeth in mandible, the teeth
five- to seven-pointed, the base narrower than the tip. Gill-rakers 7 -|- 12, to
9 -|- 13, short, the longest not quite a third as long as the eye.

Origin of the dorsal equidistant from tip of snout and base of mid-caudal rays.

Fig. 25. Cheirodon monodon Cope, a and b, premaxillary and maxillary with their teeth.

Adipose fin well-developed. Origin of anal about equidistant from snout with
last dorsal ray. Pectorals reaching ventrals, the ventrals not quite to the anal,
the fourth or fifth to the eighth to fourteenth anal rays of the male with hooks;
the ventrals in adult males also with hooks; seventeen or more interhaemals on
caudal peduncle, those of male contiguous, with broad lateral processes, especially
the anterior ones, their spines projecting from near base of last anal ray.

Scales thin, regularly imbricate, with few to many diverging radial stria?;
caudal naked; anal with a few scales in a single series at base of anterior rays.

A silvery lateral stripe; chromatophores variously developed, some speci-
mens from Cacequy are almost free from pigment, except a faint caudal spot;
in others the pigment is well-developed, the specimens appearing quite dark, the
caudal spot being well defined or more diffuse in outline, not extending upon mid-

74

MEMOIRS OF THE CARNEGIE MUSEUM.

caudal rays. The base of the anal in specimens from Porto Alegre, Cachoeira,
and Maldonado is but little, if any, longer than the caudal peduncle. In all but
one of the Cacequy specimens it is equal to the caudal peduncle and middle caudal
rays, and usually contains twenty-two rays, more rarely twenty-one, twenty-three,
or twenty-four.

There may be two, possibly three, varieties in the material at hand. If so,
they may be distinguished by the following characters:

0. Base of anal less than caudal peduncle and middle caudal rays.

b. A. 18-23, most frequentlj' 19-20; most frequently 5-5 teeth in the premaxillaries, less frequently, 4r-4
or 4-5 or 5-6; base of anal equal to the length of the caudal peduncle. Caudal spot usually well

defined. Nos. 6815, 6817, 6818 (Rio Grande do Sul) 39. monodon Cope.

66. A. 17-22, most frequently 19; usuaDy 5-5 teeth in the premaxillary; base of anal equal to the length
of the caudal peduncle or a httle longer. Nos. 846, 847, 20698 and 20699, M. C Z. (Uruguay

river basin) 38. interruptus Jenyns.

aa. A. 21-24, most frequently 22; 4-4, or 4-5 teeth in the premaxillary; base of anal equal to length of caudal
peduncle and middle caudal rays. Caudal spot diffuse. No. 6816 (Cacequy).

40. ibicuhiensis Eigemnann var. nov.

Table Showing in Detail the Number of Specimens with the Indicated Number of Premaxillary

Teeth and of Anal Rats.

Premaxillary Teeth.

Anal Rays.

4-4.

4-5.

5-5.

5-6.

6-6.

17.

18. 1 19.

20.

21.

22.

23.

24.

No. 6818, CM

No. 6815, CM

No. 6817, CM

No. 20698, M. C Z. . . .
No. 6816, CM

9

1
1
5

4
4

1
2
4

13
8
1

21

1
1

1

4

1
1

2
2

2

10
4

14

3
2
2

8

2
1
1
6
2

3

6

7

2

1

1

1

41. Cheirodon notomelas, sp. nov. f Plate XII, fig. 2.)
6812,C. M., type, 9 , 35 mm. ; 6813a-q, C. M., paratypes, nineteen, largest 40 mm.
collected in a lake, four miles from Miguel Calmone, Tiete basin. Oct. 11,
1908. Haseman.
6814, C. ]\I., one, 30 mm. Piperao Azul, lake twelve miles from Tiete. Oct. 7,

1908. Haseman.
Head 4; depth 2.5-2.66; D. 10 or 11; A. 20-22; scales usually 33 (32-34),
six to eight with pores; eye about 2.5 in the head, equal to the interorbital; depth
of caudal peduncle about equal to its length.

Compressed, dorsal and ventral profiles equally curved; preventral area rather
flat with a regular median series of eleven scales; predorsal area narrowly rounded
with a median series of ten or eleven scales; occipital process broad, reaching one-
seventh to dorsal, bordered by two and one-half scales on each side; skull convex;

eigenmann: the cheirodontin^.

75

frontal fontanel an equilateral triangle, not more than one-third as long as the
parietal; third suborbital less than half as wide as eye, in contact with the pre-
opercle along the lower limb and the angle of the preopercle, a narrow naked area
behind it, and a narrow naked strip behind the postorbitals. Mouth small, the
maxillary half as long as eye. Teeth broad-tipped, seven-pointed, the median
point prominent, especially in the premaxillary. Four teeth in the premaxillary,
two in the maxillary, and seven or eight in the mandible. Gill-rakers 5-1-7,
about one-fourth as long as the eye.

Origin of dorsal equidistant from tip of snout and base of caudal. Dorsal
pointed, its height about equal to the length of the head; adipose fin well-developed,
caudal lobes a little longer than head; origin of anal a little behind the vertical

Fig. 26. Cheirodon notomelas Eigenmann. a, anal and interhacmals of a 9 , 6813, C. M.; b, details of
the arrangement of the scales at the base of the caudal in a cf, 6S13a, C. M.

from the last dorsal ray; tip of highest ray reaching to the base of the last fourth
of the base; pectorals reaching ventrals, ventrals not (juite to anal.

Scales regularly imbricate, a few scales in a single series along base of anterior
anal rays, ten scales between dorsal and ventral, caudal lobes naked.

First dorsal rays and bases of the rest black; a sub-rhomboidal black spot
across the entire caudal peduncle, the spot bordered by unpigmented areas in front
and behind, the spot not extending to the end of the middle rays; anal dusky, the
first rays sometimes black. General color darker than usual in the genus.

Base of the anterior half of the anal of the male as usual for this genus, much
more obHque than the base of the rest of the fin; fourth to ninth anal rays of the
male much thicker than the rest, with many retrorse hooks along the posterior edges
of the middle part of the'rays.

76 MEMOIRS OF THE CARNEGIE MUSEUM.

42. Cheirodon madeirae, sp. nov. (Plate XIII, fig. 1.)

6847, C. ]M., one, 34 mm. San Joaquin, Bolivia. Sept. 4, 1909. Haseman.

A small-mouthed species, without color-markings.

Head 4; depth 3; D. 11; A. 23; scales 10 -|- 24; ten scales between dorsal
and ventrals; eye 2.4 in the head; depth of caudal peduncle nearly equal to its
length.

Moderately compressed; preventral area rounded, with a median series of
twelve scales; predorsal area rounded, with a median series of eleven scales;
occipital process extending about one-seventh to the dorsal; skull convex; frontal
fontanel a little longer than broad, less than half the length of the parietal; mouth
minute, maxillary about half the length of the eye; premaxillary with five teeth,
maxillary with two; mandible with broad, seven-pointed teeth, the median point
being a little the longer; cheeks covered b}' the third suborbital, leaving a narrow
naked wedge behind; postorbitals nearly covering the entire postorbital area.
Gill-rakers 7 + 11.

Origin of dorsal equidistant from tip of snout and base of caudal; origin of
anal under posterior part of dorsal. Caudal peduncle with about nine weak
interhaemals; ventrals not reaching anal; the pectorals reaching beyond origin of
ventrals. Scales as in other species of the genus. No color-markings.

43. Cheirodon piaba Llitken. (Plate XIII, fig. 2; Plate XVII, figs. 5-6.)
Cheirodon piaba Llitken, Oevers. Dan. Selsk. No. 3, 1874, p. 134 (Rio das Velhas);

Velhas-Flodens Fiske, 1875, p. xiv and p. 219, fig. on p. 221 (Rio das Velhas);

Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 54; -Ukey,

Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 291; Eigenmann, Reports Princeton

Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.
Tetragonopterus hellottii Ulrey (non Steindachner) : in part, Ann. N. Y. Acad. Sci.,

Vol. VIII, 1895, p. 286 (Santarem).
Cheirodon insignis Ulrey {non Steindachner) : in part, I. c. 291 (Brazil) ; Eigenmann

& Kennedy, Proc. Acad. Nat. Sci. Phila., 1903, p. 515 (Arroyo Trementina &

Arroyo Pypucu).
Cheirodon caUiuriis Boulenger, BoU. ]Mus. Torino, Vol. XV, 1900, p. 370 (Caranda-

sinho near Corumba. San Lorenzo, Prov. Jujuy, Argentina); Eigenmann,

Reports Princeton Univ. Exped. Patagonia, Vol. Ill, 1910, p. 429.
Cheirodon interruptus Eigenmann & Kennedy (non Jenyns), Proc. Acad. Nat. Sci.

Phila., 1903, p. 514 (Campo Grande; brook near Arroyo Trementina);

Ann. Carnegie INIus., Vol. IV, 1907, p. 126 (Puerto Max); Eigenmann & Ogle,

Proc. U. S. Nat. Mus., Vol. XXXIII, 1907, p. 9.

eigenmann: the cheirodontin^. 77

Cheirodon micropterus Eigenmann, Proc. U. S. Nat. Mus., Vol. XXXIII, 1907, p. 9

(Santarem); Reports Princeton Univ. Exped. Patagonia, Vol. Ill, p. 429.

Range: Abundant in Rio Paranahyba, Rio San Franci.sco, upper Parana,
and Paraguay; rare south of these points, and in Amazons.

The very large number of specimens recorded below, most of them in excellent
condition, together with the specimens recorded by me in the papers quoted above,
enables me to revise the synonymy and bibliography of this species. As stated
by Eigenmann & Ogle a comparison of one of the types of calliurus with specimens
recorded by me as interruptus showed that these specimens belong to the same
species. At the same time the opinion was expressed that these specimens were
probably distinct from interruptus. The material at hand shows that the Para-
guayan specimens are specifically identical with C. piaba, originally recorded from
the Rio das Velhas and found abundantly throughout the Rio San Francisco.

The type of micropterus is poor, but is \exy probably also a C. piaba.

Aside from the specimens previously recorded, some of which are again
enumerated, I have examined many specimens collected by Mr. J. D. Haseman.

6821a-b, C. M., two males, largest 33 mm. Aregua, Paraguay. April 8, 1909.
Haseman.

6822a-g, C. M., seven, two males, 33 and 39 mm., two females, 36 and 39 mm.
three females, the largest 30 mm.'^ Corumba, Paraguay. April 27, 1909.
Haseman.

6824a-p, C. M., seven males, largest 38 mm.; nine females, largest 38 mm.
Puerto Suarez. May 6, 1909. Haseman.

9984, I. U. M. 933a-b, C. M., ten, largest 42 mm. to base of caudal. Campo
Grande. Anisits.

9997 and 10122, I. U. M.; 926a-b, C. M., sixteen, largest 31 mm. to base of

caudal. Arroyo Pypucu. Anisits.
6825a-h, C. M., nine, largest 35 mm. Asuncion, Paraguay. March 28, 1909.

Haseman.
10289, I. U. M., Colonia Gonzales. Anisits.
6826a-b, C. M., two, 2V' and 44 mm. Caceres. May 27, 1909. Haseman.

9985, I. U. M. 953a-b, C. M., thirteen, largest 40 mm. to base of caudal.
Arroyo Trementina. Anisits.

6908a-f, C. M., six, 15^*-20 mm. Caceres. May 24, 1909. Haseman.

" In these smaller specimens and in the two males, the caudal spot extends further on the caudal than
in the two larger females.

" The smaller has only one tooth on the maxillary.

" In the smallest the color is most profuse and the caudal spot extends to near tip of the middle rays.

78 MEMOIRS OF THE CARNEGIE MUSEUM.

6823a-u, C. M., twenty -one, largest 39 mm. Lagoa de Parnagua. Jan. 17, 1908.

Haseman.
6827a-k, C. ^I., one male, twelve females, largest 43 mm. Rio das Velhas,

tributary of Rio San Francisco. ^lay 13, 1908. Haseman.
6828a-x, C. M., twenty-one males, largest 38 mm.; thirty -two females, largest

38 mm. Pirapora, Rio San Francisco. Dec. 15, 1907. Haseman.
6829a-b, C. M., two. Lagoa Pereira, San Francisco basin. Dec. 23, 1907.

Haseman.
6830a-b, C. jM., two. Lagoa de Porto, San Francisco basin. Dec. 24, 1907.

Haseman.
6831a-x, C. ^L, seven males,''' largest 37 mm., twenty-seven females, largest

39 mm. Barreiras, Rio San Francisco. Jan. 4, 1908. Haseman.
6832a-g, C. M., seven, largest 31 mm. Boqueirao, near mouth of Rio Preto,

San Francisco basin. Jan. 6, 1908. Haseman.
6833a-x, C. M., twenty-eight, largest 38 mm. Santa Rita, San Francisco basin.

Jan 26, 1908. Haseman.
6834a-e, C. M., five,'' largest 39 mm. Penedo at mouth of Rio San Francisco.

:March 22, 1908. Haseman.
6835a-c, C. ]M., three. Rio Coite, San Francisco basin. Nov. 6, 1907.

Haseman.
6846a, C. M., one, 40 mm. Lagoa Salgado, San Francisco basin. Nov. 10, 1907.

Haseman.
6838a-d, C. AL, four, largest 35 mm. Rio Itapicm-u, Fazenda de Amaratu, 6

miles north of Bom Fin. Nov. 21, 1907. Haseman.
6836a-f , C. M., six, largest 33 mm. Rio de Jacobina, tributary of Rio Itapicuru.

A. 19-21. Haseman.
6837a-b, C. M., two, largest 39 mm. Queimadas, Rio Itapicuru. March 2, 1908.

Haseman.
6839a-h, C. IM., eight, 39 mm. Alagoinhas, Rio Catu. :March 4, 1908.

Haseman.
6840a, C. M., one, 35 mm. Cachoeira, Rio Paraguassu. April 14, 1908. Hase-
man.
6842a-x, C. M., twenty-five, largest 42 mm. Bebedouro, near Rio Grande and

Rio Parana. Sept. 1, 1908. Haseman.
6844a, C. M., one male, 25 mm. Santa ]Maria, Rio Vaccacahy-^NIirim, tributar}'

of the Jacuhy, Rio Grande do Sul. Jan. 29, 1909. Haseman.

^ Color prominent, spot extending to end of middle ra)'s in some. Depth 2.33-2.8.
" With ripe eggs.

eigenmann: the cheirodontin^e. 79

6843a-x, C. M., thirty-five, largest 38 mm. Jaquara, Rio Grande, into Rio
Parana. Aug. 18 and 19, 1908. Haseman.

6845a-e, C. M., five, largest 41 mm. Cacequy, secondary tributary of the Rio
Uruguay. Jan. 31, 1909. Haseman.

Head 3.6-4.5; depth 2.25-3; D. 11; A. 19-27 most frequently 22 or 23; scales
31-36, most frequently 33 or 34, 9-12 with spines; eye equal to interorbital,
about 2.5 in the head; depth of caudal peduncle 1.25 in its length; base of anal
much longer than caudal peduncle.

Compressed, depth very variable, the dorsal and ventral profiles symmetric,
nearly equally arched; preventral area flat, with well-marked lateral edges, eleven
to thirteen scales in a median series; predorsal area keeled, with ten scales in a
median series, which is regular to near the occipital process; occipital process short,
extending one-sixth to one-seventh to the dorsal, bordered by two or three scales;

Fia. 27. Cheirodon piaba Liitken. a, premaxillary; b, maxillary.

frontal fontanel an equilateral triangle, 2.5-3.5 in the length of the parietal fon-
tanel; interorbital convex; third suborbital covering the entire cheek, or a verj-
narrow naked wedge behind it; lower one of the postorbitals as wide as the third
suborbital at its tip, sometimes covering the entire width to the preopercle; the
upper postorbital much narrower, leaving a wider naked strip; mouth minute,
maxillary not, or barely, reaching the eye, nearly vertical, very little more than
half the length of the eye; maxillary with one tooth in three specimens, two teeth
in sixty-two specimens, and three teeth in seven specimens examined; prcraaxillarj'^
with five teeth; mandible with about seven teeth; teeth sometimes black-tipped.
Gill-rakers about 6 -f- 11, not over one-fourth as long as eye.

Origin of dorsal equidistant from tip of snout and base of caudal, the highest
ray a little over length of head; origin of anal a little behind vertical from base of
last dorsal ray; pectorals reaching to, or beyond, origin of ventrals, ventrals not
to anal; eight to thirteen rays of the anal (beginning with the second or third) of the
male with hooks, base of the hook-bearing portion of the anal, making an angle with
the base of the rest of the fin; all but the outer two ventral rays with similar hooks;

80

MEMOIRS OF THE CAENEGIE MUSEUM.

base of anal about equal to length of caudal peduncle plus the middle caudal rays ;
the interha^mals, nine to thirteen in number, occupy four-tenths to six-tenths of
the distance between the base of the last anal ray and the caudal, beginning a
little behind the tip of the last anal ray. Those of the male without lateral proc-
esses, sometimes with a low ridge or keel running along the sides of the anterior
ones and ending in a knob in front of them; lower caudal fulcra prominent, con-
tinuous with the interha?mals. Scales normal.

There is a caudal spot of varying size and intensity, sometimes extending

Fig. 28. Chdrodon piaba Liitken. o, region between anal and caudal in 9 ; 6, Do. in &. Lagoa
Paranagua, 6823, C. M. ; c, anal fin and caudal fulcra and interhscmals of a' , 6828, CM.;d, skeleton of fulcra and
interhtemals of cf , 6843, C. M. (All figures greatly enlarged.)

entirely across the end of the caudal peduncle, sometimes extending on the middle
caudal rays, rarely to their tips; a faint black line overlaid with silvery along the
middle of the sides; anterior margin of dorsal dark; general color very pale or
quite dark, depending on the nature of the locality from which the specimens came.
It is possible that we should refer to this species a small specimen, 6909, C. M.,
15 mm. long, taken in a tributary of the Guapore about forty miles south of Villa
de Matto Grosso.

44. Cheirodon microdon sp. nov. (Plate XIV, fig. 1.)
This species is allied to Cheirodon stenodon and to Aphjpcheii'odon hemigrammus. isivv>-X^-
6850, C. M. Type, 42 mm. 6851a-b, C. M., paratypes two, the larger 41 mm.,
Caceres, Upper Paraguay, May 24, 1909. Haseman.

eigenmann: the cheirodontin^.

81

Head 4-5; depth 3; D. 11; A. 23-25; scales in a median line are 34-36, of
which 10-11 are with pores; ten and one-half scales between dorsal and ventrals.
Eye 2.75 in head, very little greater than interorbital.

Compressed, slender; dorsal and ventral profiles nearly equally curved; pre-
ventral area flat, with rather well-defined lateral angles, and with a nearly regular
median series of twelve scales; predorsal area with a median series of eleven scales;
occipital process extending one-sixth to one-seventh to the dorsal, bordered by
three scales on each side; frontal fontanel triangular, the sides of the triangle but
little longer than the base, about 2.5 in the length of the parietal fontanel; mouth
large, maxillary three-fourths as long as eye; teeth five-pointed; the median points

Fig. 29. Cheirodon microdon Eigenmann. a, outline of side of head; b, top of head, showing fontanels;
c, premaxillary; d, maxillary; e, ma.xillary ; g, dentition; h, details of intemeurals and interhsemals, 6850, C. M.

of the premaxillary projecting considerably^ beyond the lateral points, the tliree
median points of the teeth of the lower jaw about equal, the extreme lateral points
minute; seven to nine teeth in the premaxillary, two in the maxillary; teeth in
front of the lower jaw rapidly graduated from the third to the sixth; sides of
lower jaw upturned, with several (about six) minute, conical teeth; third suborbital
leaving but a very narrow wedge-shaped naked area behind; postorbitals covering

82

MEMOIRS OF THE CARNEGIE MUSEUM.

half to two-thirds of the postorbital area. Gill-rakers 7 + 13, the longest about
one-third as long as eye.

Origin of the dorsal very little nearer tip of snout than to middle caudal rays,
the highest ray a little greater than the head; adipose fin well developed; origin
of anal below the posterior part of dorsal. Ventrals not reaching anal, the pectorals
about to the origin of the ventrals.

Scales thin, regularly imbricate, with few diverging radial stride. Caudal
naked; anal with a few scales in a single series along base of anterior rays.

Interhsemal spines of the caudal peduncle feeble, about eight to ten in number.

A faint caudal spot, not directly continued forward as a dark band; upper
part of the anterior dorsal rays dark. A silvery lateral stripe.

The three specimens here described appear to be females. They are probably
from an area in which the color-cells do not reach their fullest pigmentation. The
species distinctly differs from C. stenodon in the character of the teeth.

45. Cheirodon stenodon, sp. nov. (Plate XIV, fig. 2.)
6848a, C. M., type, 33 mm., 6849a-x, C. M., paratypes, over thirty, largest 34

mm. Bebedouro, near Rio Grande and Rio Parana. Sept. 1-5, 1908.

Haseman.
A long-jawed, small- toothed, slender species, with feeble interhsemals.

Fig. 30. Cheirodon stenodon Eigenniann.
e-f, symphyseal line.

a, b, c, premaxillarj', maxillary, and mandible; d, dentition;

Head 4; depth a little more than 3; D. 10; A. usually 20 or 21, rarely 18, 19,
or 22; scales in a median series 36 or 37, rarely 32; six to eleven scales with pores;
eight to ten scales between dorsal and ventrals; eye 2.75 in head, equal to the inter-
orbital; depth of caudal peduncle about 1.33 in its length.

eigenmann: the cheirodontin.e. 83

Compressed, slender; dorsal and ventral profiles nearly equally curved; pre-
ventral area rounded, with a nearly regular median series of twelve to thirteen
scales; predorsal area rounded, with a perfect median series of nine to ten scales;
occipital process extending one-sixth to one-seventh the distance to the dorsal,
bordered by three scales on each side; frontal fontanel equilateral, less than half
as long as the parietal; skull convex, smooth between the eyes.

Maxillary comparatively long, at least two-thirds as long as eye, its free margin
a little convex; teeth narrow, the sides nearly parallel; a large median point and
two small points on each side, those of the front of the lower jaw slightly broader
than those of upper jaw; premaxillary teeth five to seven; maxillary teeth two;
mandibulary teeth six to nine, the first four of nearly equal size, those on sides
rapidly graduated, the last ones conical; third suborbital covering the cheek below,
leaving only a narrow naked wedge behind it. Postorbitals covering about two-
thirds of the width of the postorbital area. Gill-rakers 6 -|- 12.

Origin of the dorsal equidistant from snout and middle caudal rays, the dorsal
pointed, its highest ray about equal to length of head. Adipose fin well-developed.
Origin of anal under the vertical from posterior part of the dorsal. The interhsemals
of the caudal peduncle weak, very few, about five, if at all developed, not projecting
in any of these specimens. Ventral not reaching anal. Pectorals long, reaching
to or nearly to the ventrals. None of the anal rays have hooks; it is probable
therefore that the specimens are all females.

Scales regularly imbricate, with a few diverging radial striae; caudal naked.
Anal with a few scales along the base of the anterior rays.

Straw-colored, the scales of the back margined with a row of chromatophores;
a large triangular caudal spot not extending to the end of the middle rays, continued
forward along the middle of the sides as a narrow band to in front of dorsal. Tip
of dorsal and membranes between first and second and upper half of second and
third dark.

Genus XX. Holesthes''^ Eigenmann.
Holoshesthes Eigenmann, Smiths. Misc. Coll. Quarterly, Vol. XLV, 1903, p. 144.

Type : Cheirodon pequira Steindachner.

Very similar to Aphyocheirodon and Odontostilbe.

Teeth notched, in a single scries, six or seven in the premaxillarj', rather
narrow, but little expanded toward tip, more or less ovate, with five to seven
notches, of which the median one is a little the larger, the rest being lateral ; mandib-

^ aXos = complete; iaOns, i) = clothing, in allusion to the complete dentition of the maxillary. I here
take opportunity to amend the spelling of this generic name.

84 MEMOIRS OF THE CARNEGIE MUSEUM.

ulary teeth much expanded at the tip, with a small Ijasal notch on each side and
three median points of about the sayne size and extent. Maxillary with few teeth,
broad-tipped, the points nearly alike. Mouth moderate; third suborbital in con-
tact with the preopercle below; frontal fontanel short; adipose fin well -developed;
origin of anal below end of dorsal; caudal naked; lateral line complete; scales with
very few radial stria?; interhajmals of the caudal peduncle not projecting.
Minute fishes of southern and eastern Brazil and Paraguay.

Key to the Species of Holesthes.
a. Dorsal with a large, oblique, black wedge extending from the upper part of the anterior ray toward the
middle of the sixth ray; male with the outer ventral and first developed dorsal ray filiform.

46. pequira (Steindachner).

aa. Tip of dorsal faintly dusky; interhtemals of the caudal pedimcle of the male much stronger than the inter-

neurals; outer ventral ray and first dorsal rays not filiform 47. heterodon Eigenmann.

46. Holesthes pequira (Steindachner). (Plate XV, fig. 1.)
? Salmo pequira Natterer, MS.
Cheirodon pequira Steindachner, Anz. Ak. Wiss. Wien, 1882, p. 180 (Rio Guapore) ;

Flussf. Slidam., Vol. IV, 1882, p. 38 (Cujaba); Eigenmann & Eigenmann,

Proc. U. S. Nat. Mus., Vol. IV, 1891, p. 54; Ulrey, Ann. N. Y. Acad. Sci.,

Vol. VIII, 1895, p. 290; Boulenger, Boll. Mus. Univ. Torino, Vol. XII, 1897

(Caiza; Mission de San Francisco).
Holoshesthes pequira Eigenmann, Smiths. Misc. Coll. Quarterly, Vol. XLV, 1903,

p. 144; Reports Princeton Univ. Exp. Patagonia, Vol. Ill, 1910, p. '429.
Odontostilbe trementince Eigenmann and Kennedy, Proc. Acad. Nat. Sci. Phila.,

1903, p. 513 (Arroyo Trementina); Eigenmann, Ann. Carnegie Mus., Vol. IV,

1907, p. 125 (Puerto Max); Reports Princeton Univ. Exped. Patagonia, Vol.

Ill, 1910, p. 429.

Range : Upper Madeira, Paraguay.

In the original description of pequira Steindachner states that the entire

Fig. 31. Holesthes pequira (Natterer). a, maxillary; b, premaxillary.

anterior edge of the maxillary is finely dentate and that the caudal spot is very
small. If Steindachner's statement is correct then trementince is a valid species

eigenmann: the cheirodontin.e. 85

and the type of a distinct genus. But the statement was probably made without
microscopic preparations. Furthermore the specimens had been in alcohol for
fifty-eight years when the description was prepared and it is possible that they
were faded and the caudal spot small in consequence. Except for these two char-
acters the description of pequira applies very well to specimens of trementince and
indeed in two of the specimens enumerated below the caudal spot is quite small.
There is no other species known from the upper Paraguay related to these, which
has an oblique bar on the upper part of the dorsal.

Specimens sent me from the British Museum as pequira are Odontostilbe
microcephala.

7317«, C. M.; 9987, 1. U. M., nine, type and paratypes of trementince. Arroyo
Trementina. Anisits.

9986 and 9987, I. U. M. Brook near Arroyo Trementina.

6857a-l, C. M., twelve, largest 43 mm. Villa Hays, Paraguay. April 13,
1909. Haseman.

10187, I. U. M., one, Puerto Max. Anisits.

6858a-e, C. M., five,'^ largest 31 mm. Asuncion, Paraguay. March 28, 1909.
Haseman.

6859a, C. M., one, 35 mm. Caceres, Paraguay. May 27, 1909. Haseman.

6860a-b, C. M., two, largest 43 mm. Corumba, Paraguay. April 27, 1909.
Haseman.

6861a-h, C. M., eight, largest 45 mm. Sapucay, Paraguay. April 2, 1909.
Haseman.

6862a-e, C. M., five, largest 56 mm. Cacequy, Rio Ibicuhy. Feb. 1, 1909.
Haseman.

6877a-c, C. M., three, largest 55 mm. Santa Maria, Rio Maccacahy Mirim.
Jan. 29, 1909. Haseman.

Head 4.5; depth 3-3.5; D. 11; A. ^/, -3^, ¥, ¥, ¥; scales 6-¥,^,^f, ^, ^
— 4; eye 2.75-3 in the head, equal to, or a little greater than, interorbital ; depth of
caudal peduncle about 3 in the depth, 1.5 in its own length.

Compressed, elongate; the dorsal and ventral profiles equally arched; the pre-
ventral area flat, with a nearly regular median scries of thirteen scales; predorsal
area rounded or bluntly keeled, with about ten scales; occipital process one-sixth
in the distance from its base to the dorsal, bordered by two or three scales; frontal
fontanel a little longer than wide, triangular, its length a little more than two in
the parietal fontanel; mouth small, the maxillary scarcely reaching to below the

^ Caudal spot minute in two.

86 MEMOIRS OF THE CARNEGIE MUSEUM.

anterior margin of the eye. Teeth of the upper jaw narrow, with a large median
point and three small points on the side of the tooth; teeth of lower jaw much wider,
broad-tipped, with five points, three of these of equal size and prominence, the
lateral points minute and much below level of the other three; maxillary usually
with two or three teeth, rarely four; premaxillary teeth six and six or six and seven;
mandible with about six notched, graduated, teeth followed on the side with about
three minute, conical teeth; second suborbital and lower postorbital leaving but
a narrow, naked area between them and the vertical limb of the preopercle.
Gill-rakers 7 -f 12.

Origin of dorsal equidistant from tip of snout and some distance behind tip of
adipose, its height little greater than length of head. The first ray in the male pro-
longed into a filament, which sometimes reaches the adipose fin. Anal emarginate,
its origin below the base of the last dorsal raj', base equal to length of head and
about one-fourth of pectoral; ventral usually not reaching anal, its outer ray
sometimes (in some males) filiform, reaching beyond origin of anal; origin of ven-
trals in front of the vertical from the first dorsal ray; pectorals not quite reaching
ventrals in female, a little beyond their base in some males; no prominent inter-
hsemals in males or females; about seven (beginning with the first fully developed)
rays of the anal of the male with hooks.

Scales thin, regularly imbricate, with few if any radial strise; caudal naked;
a small sheath at the base of the anterior anal rays; lateral line but little decurved.

Distinguished from the other members of the genus by the large dorsal spot,
which is wedge-shaped from the upper part of the first fully developed dorsal ray
(the second) to the middle of the sixth or seventh ray; sometimes a minute black
spot near the middle of the first fully developed anal ray; caudal peduncle usually
with a large, conspicuous spot, which extends a little way on the middle caudal
rays and usuall}^ upward and downward across the entire caudal peduncle. The
caudal spot more rarely (6858a-b) very small, circular. A well-defined silver j'^
lateral band.

The specimens from the province of Rio Grande do Sul, Nos. 6862 and 6877,
are larger than the rest. The caudal spot is restricted, ovate, but faintly extended
upward and downward. They are slenderer, depth 2.33-2.66; with the six inter-
hsemals and nine intcrneurals of the caudal peduncle of the male equally well-
developed.

As there is still a little doubt about their identity, I add the original description
of pequira as given by Steindachner, I. c. :

(P. 38) "Seitenlinie voUstandig; Korperform sehr gestreckt. Bauchlinie bis

EIGENMANN: the CHEIRODONXINiE. 87

zur Ventrale bald mehr, bald minder bedeutend gebogen und in der Regel ein
wenig schwacher zur Bauchflossc abfallend, als die nur sehr wcnig gebogene Riicken-
linie zur Dorsale ansteigt. Dorsale in der Mitte der Korpcrliinge, hinter der Basis
der Ventralen (in verticaler Richtung) beginnend. Silberfarbige Seitenbinde unter-
halb der Dorsale bis zur Caudale scharf ausgepragt, weiter nach vorn an den
Randern verschwommen. Caudalfleck sehr klein, doch deutlich sichtbar. Humer-
alfleck in der Regel fehlend, oder nur ausserst schwach angedeutet. Eine durch
starke Anhaufung dunkler Punkte gebildete schrage Binde in der oberen Hiilfte
der Dorsale.

"Stirn queriiber gewolbt. Mundspalte sehr klein. Oberkiefer am ganzen
vorderen Rande sehr fein gezdhnt.

"Leibeshohe 33^mal, Kopflange 3^mal in der Korperlange; Augendiameter
23^-2^4mal, Stirnbreite nahezu 3mal, Schnauzenlange fast 4mal in der Kopflange
enthalten.

(P. 39) "Die Hohe der Dorsale erreicht eine Kopflange; die stark zugespitz-
ten Caudallappen sind merklich langer als der Kopf. Die Spitze der Ventrale
reicht genau bis zum Beginn der Anale, die der Pectoralen nahezu bis zur Basis
der Ventralen. Rumpf hell goldgelb, gegen die Bauchseite herab hcUgelb.

"D. 11. A. 22. L. lat. 35-36 (bis zur Basis d. Caudal.). L. tr. 6/1/4.

"Zahlreiche Exemplare bis zu 38 mm. lange, von J. Natterer im Jahre 1824
(Send. VIII, Nr. 59) im Cuyaba gesammelt, und Salmo pequira gennant."

47. Holesthes heterodon sp. nov. (Plate XV, fig. 2.)

Range: Rio San Francisco to Rio Ribeiro.

6875a, C. M., type, female. 48 mm. Jaguara, Rio Grande emptying into
Rio Parana, August 18, 1908. Haseman.

Paratypes all of the following:

6876a-x, C. M., twenty-seven, largest 49 mm. Jaguara, Aug. 18, 1908.
Haseman.

6864a-p, C. M., sixteen, largest 50 mm. Setc Lagoas, May 5, 1908. Haseman.

6865a-x, C. M., twenty -six, largest 50 mm. Bebedouro near Rio Grande and
Rio Parand, Sept. 1, 1908. Haseman.

6866a-h, C. M., eight, largest 38 mm. Pirapora, Dec. 5, 1908. Haseman.

6867a, C. M., one, 36 mm. Rio das Velhas, May 18, 1908. Haseman.

6868a-e, C. M., five, largest 38 mm. T.agoa Pereira, Dec. 23, 1907. Haseman.

6869a-c, C. M., three, largest about 41 mm. Rio Zinga, Nov. 7, 1907. Hase-
man.

88

MEMOIRS OF THE CARNEGIE MUSEUM.

6870a, C. M., one, 28 mm. Barreiras, Lagoa of Rio Grande, San Francisco

basin, Jan. 3 or 4, 1908. Haseman.
6871a-o, C. M., fifteen, largest 46 mm. Sao Joao del Rei, May 17, 1908.

Haseman.
6872a-d, C. M., four, largest about 48 mm. Sao Joao del Rei, May 17, 1908.

Haseman.
6874a, C. M., one, 38 mm. Pencdo, March 22, 1908. Haseman.
6873a, C. M., one, 40 mm. Queimadas, Rio Itapicurii, March 2, 1908.

Haseman.
6878a, C. M., one, 48 mm. Iporanga, Dec. 1, 1908. Haseman.
This species is very closely allied to pequira, differing in the characters noted
in the key. It is almost identical in characters with Odontostilbe microcephala.

<KIT)P]

Fig. 32. Holesthes helerodon Eigenmann. a, maxillary; 6, premaxillary ; c, mandible.

Head 4.25-4.75; depth 3-3.5; D. 11, very rarely 10; A. 19-24 most frequently
20 in specimens from Jaguara and Bebedouro; most frequently 22 in specimens
from Pirapora and Sete Lagoas of the San Francisco basin. Scales 5 or 6-^,
^, fi, ^/-4 (35 being more frequent in the specimens from the San Francisco;
36 more frequent in specimens from Jaguara and Bebedouro). Eye 3 in head,
equal to interorbital; depth of caudal peduncle 2.5 in the depth, 1.5-1.75 in its
length.

Compressed, elongate; the dorsal and ventral profiles equally arched; pre-
ventral area flat or rounded, with about thirteen scales; predorsal rounded, with

eigenmann: the cheirodontin^. 89

ten to twelve scales in a series which is regular, except at about the sixth scale from
the occipital process; occipital process about one-sixth in the distance to the dorsal;
bordered by two or three scales; frontal fontanel a little longer than wide, a little
more than twice the length of the parietal; maxillarj^ reaching to below anterior
margin of eye; teeth as in C. pequira, premaxillary teeth in those examined ^,
"!-> T^ ) "T^ ; maxillary teeth ranging from one to four most frequently two and
two in San Francisco specimens, most frequently three and three in Jaguara and
Bebedouro specimens; mandible with about six graduate teeth and a few minute
ones on the side; third suborbital and lower postorbital leaving but a very narrow
naked strip behind them. Gill-rakers 6 or 7 -|- 11 or 12.

Origin of dorsal about equidistant from tip of snout and the interneurals of
the caudal peduncle, distinctly behind the vertical, from the origin of the ventrals;
origin of anal under base of last dorsal ray. Dorsal rays of male not prolonged;
height of dorsal a little greater than length of head; base of anal a trifle longer
than height of dorsal; the first five or six fully developed anal rays of the male
broad, with hooks; the ventral profile from origin of anal to caudal concave;
ventrals usually just reaching anal in male; pectorals just reaching ventrals, these
fins a little shorter in the female; ventral rays of the male with some hooks below.

Scales thin, regularly imbricate with a few widely divergent radial stride.
Caudal naked; anal with a very rudimentary sheath at the base of the anterior rays.

Lateral line complete, except in one specimen from Sete Lagoas and in nine
specimens from Jaguara, in which the pores were:

Left. Right.

4^3-3-2-1-23 4-3_3_3^^3_iL_i_4_8

36 34-2
10-3-1-1-1-6-12-2 14-5^1r-3-9

37 4-2-29-2
10-2-6-3-4-6-5-? 13-2-3-1-1-2-3-1-8-2
30-2-1-2-1 4^5-5-6-5-2-9-?
16-2-17 34+(?)
2-21-5-3-3-2 7_5_7_2-i5

? (10-2^)-2-13 7-3-5-4-17-1

8-3-2-2-3-1-10-4-1 5-3-6-1-1-1-1-1-13-1-3

The heavy-faced figures indicate scales with pores. It is seen that many
sorts of breaks occur. The pores may not be developed in front, at the end, or at
any point along the lateral line, and at different points on the two sides.

90 MEMOIRS OF THE CARNEGIE MUSEUM.

An ovate spot at the end of the caudal peduncle, continued a little way on
the middle rays; tip of dorsal variously dusky, a distinct narrow, silvery, lateral
band.

Genus XXI. Odontostilbe" Cope.
Odontostilbe Cope, Proc. Am. Phil. Soc, 1870, p. 566.

Type : Odonlostilhe fugitiva Cope.

Teeth notched, in a single series, those of the premaxillary and mandible
similar, with a large median point and smaller lateral points; maxillary with a
few broad-tipped teeth; third suborbital in contact with the pre-opercle below;
adipose fin well-developed; origin of anal under end of dorsal; caudal naked;
lateral line complete; scales with few radial strise; interhsemals feeble, not pro-
jecting.

^Minute fishes found from Panama and Trinidad to the La Plata and the
Peruvian Amazon.

But few of the species of this genus are distinguishable at sight. 0. melandeta
maj' be distinguished by the absence of a proper caudal spot; imraguayensis dSid
madeirce by their deep form, they are quite similar; drepanon by its filamentous
fin-rays. 0. microcephala and fugitiva are very similar. 0. hastata stands quite
alone, but looks like microcephala. 0. microcephala differs from Holesthes heterodon
largely in the structure of the teeth of the lower jaw.

It is possible that 0. hastata and 0. melandeta do not belong to this genus.

Key to the Species of Odontostilbe.
a. Caudal in the male vdi\\ a pouch covered by scales just below the shortest rays at the middle. Eye 3;
A. 18-21 ; rays of lower caudal lobe of male with retrorse hooks, an intense well circumscribed spot on the

caudal peduncle 48. hastata Eigenmann.

aa. Caudal naked in the male.

h. A large conspicuous caudal spot; teeth large; 5-7 in the premaxillary, 1-4 in the maxillary.
c. Male with the outer ventral and first developed dorsal rays filamentous. D. 10 to 12.

49. drepanon Fowler.
cc. Male without filamentous rays.
d. Dorsal with 10 or 11 rays.

e. Depth about 3.25; A. 22-34; scales 35 to 37; mouth minute, maxillary half the length

of the eye - 50. fugitiva Cope.

ee. Depth 3 to 4; A. 18-22, scales 34^37; mouth moderate, maxillary more than half the

length of the eye 51. microcephala Eigenmann.

eee. Depth 2.5 to 2.75; A. 22-25; scales 33 or 34; caudal spot indistinct.. .52. pulchra Gill.

eeee. Depth 2.6 to 3; A. 21-24; scales 32-35; mouth minute. IMaxillary half the length of

the eye 53. paraguayensis Eigenmann & Kennedy.

*» oioiis, b = tooth; arixfiri, 17 = a lamp, possibly in allusion to the brilliant teeth.

eigenmann: the cheirodontin^e. 91

dd. Dorsal with 12 or 13 rays; depth 2| to 3; A. 23-24; scales 34 to 37; mouth minute;

maxillary half the length of the eye 54. madeirse Fowler.

66. No distinct caudal spot; caudal peduncle narrowly margined with dark; depth 3.6; A. 21; scales 34 or
35; premaxillary with 10 to 14 teeth, maxillary with 4 to 7 55. melandeta Eigenmann.

48. Odontostilbe hastata Eigenmann. (Plate XVI, fig. 1.)
Odontostilhe hastatus Eigenmann, Indiana University Studies, No. 18, 1913, p. 27.
Range : Magdalena and Atrato basins.
5703, C. M., type, d", 40 mm.; paratypes, twenty-five, largest 37 mm.

5104 a-j, C. M. 12861a-j, I. U. M., Soplaviento. Eigenmann.
5365a, C. M., Certegui. Rio Quito, into Atrato. Wilson.
5387a-f, C. M., 13079, I. U. M., many, Rio Atrato at Quibdo. Wilson.
5366a-x, C. M., 13045, I. U. M., many, Rio Truando, into Atrato. Wilson.
Head 4 +; depth 2.8-3.25; D. 11; A. most frequently 19 (18-21); scales

Fig. 33. Odontostilbe hastata Eigenmann. Caudal scales of cT.

5.5-32 to 35-3; eye 3 in the head, equal to intcrorbital. Most nearlj^ like Odon-
tostilbe paraguayensis, but much slenderer.

Compressed; dorsal and ventral profiles equally arched; prevontral area
rounded, with about eleven scales; postventral and predorsal areas narrowly
rounded, the latter with a regular median series of about ten scales; occipital
process short and broad, its length one-sixth of the length from its base to the dorsal,
bounded by three scales on each side; frontal fontanel variable, an equilateral
triangle as wide as, and half as long as, the parietal fontanel, or (piito minute;
skull convex; snout blunt, the mouth comparatively large; maxilhiry-iircmaxillary
nearly as long as the eye; five teeth in the premaxillary, two or three in the maxil-

92 MEMOIRS OF THE CARNEGIE MUSEUM.

lary; four broad-tipped, seven-pointed teeth in the dentary in front and with as
many as four graduated teeth on the side. Second suborbital covering the entire
cheek. About ten rakers on the lower arch of the gill.

Dorsal pointed, its highest ray longer than head, reaching to within two or
three scales of the adipose, its origin about equidistant from tip of snout and caudal;
middle caudal rays very short; a pouch on the caudal of the male just below the
middle ra.ys covered with scales; in the male the rays of the lower caudal lobe
with retrorse hooks, similar to those of the five anterior anal rays in the male;
anal short, its margin sub truncate (very slightly emarginate), its rays graduate, the
tip of the highest (the third) reaching to last fourth or to base of the last ray; anal
base 3.75-4.6 in the length, its origin behind the vertical from the last dorsal ray;
origin of ventrals in front of the vertical from the anterior dorsal ray, about
reaching the anal; pectorals not quite reaching ventrals or slightlj" beyond their
base.

Scales thin, regularly imbricate, with as manj^ as ten radial striae; lateral
line complete, nearly straight; anal sheath consisting of a single row of scales along
the bases of the anterior rays; caudal naked, except for a basal sheath on the lower
lobe of the male and the peculiar scales just below the middle rays in the male.

Scales of the back margined with dark; margins of the mj^otomes above the
anal marked with chromatophores; no humeral spot; a silvery band; a conspicuous
black spot on the end of the caudal peduncle, rounded in front, pointed on the bases
only of the middle caudal rays; peduncle in front of the spot without chromato-
phores. Orange in life above and behind caudal spot.

One specimen from the Calamar Cienega, 32 mm., C. M. No. 5105, and three,
the largest 30 mm., C. M. No. 5106, 1. U. M., No. 12862, may belong to this species.
Chromatophores are limited to the dorsal region and to along the base of the anal;
the caudal spot is smaller, oval.

49. Odontostilbe drepanon Fowler.

Odontostilbe drepanon Fowler, Proc. Acad. Nat. Sci. Phila., 1913, p. 529. (Tribu-
tary of the Madeira river near Porto Velho.)
Range: Madeira basin.
This species is known from the types only. It is quite possible that it will

prove to be synonymous with 0. fugitiva.

Head 3.25; depth 3-1/6; D. 10; A. 24; scales 6-38-5; 9 predorsal scales;

eye 3.25 in the length of the head, maxillary 3.5; interorbital 2.87; depth of caudal

peduncle 2.66.

eigenmann: the cheirodontin^.

93

Elongate, well compressed; mouth small, terminal; lips moderate; maxillary
not reaching eye; teeth with five to seven points, maxillary with two teeth; sub-
orbital completely covering cheek. Origin of dorsal midway between tip of snout
and tip of adipose; third dorsal ray prolonged and filamentous, nearly to origin of
the adipose; origin of anal behind base of dorsal, third ray longest, thence gradually

Fig. 34. Odontoslilbe drepanon Fowler. (After Fowler, Proc. Acad. Nat. Sci. Fhila., 1913, p. 529.)

diminishing; pectorals reaching ventrals; origin of ventrals in front of dorsal, first
ray produced in a filament, which extends beyond the origin of anal.

Base of caudal with a dusky blotch a little larger than the eye, not continued
to the end of the middle rays. No humeral spot. Fins all pale.

50. Odontostilbe fugitiva Cope.
Odontoslilbe fugitiva Cope, Proc. Am. Philos. Soc, 1870, p. 566, fig. (Pebas);

Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV, 1891, p. 54;

Eigenmann, Reports Princeton Univ. Exp. Patagonia, Vol. Ill, 1910, p. 429.
Cheirodon fugitiva Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 290. (Lower

Amazon.)

Range: Amazon basin.

6863a-d, C. M., four, largest 41 mm. San Antonio de Rio Madeira. Nov. 3,
1909. Haseman.

Head 4.5; depth 3.25-3; D. 11; A. 22 or 23; scales 37. Eye 2.75-3 in the
head, .6 in snout, equals interorbital; depth of caudal peduncle 3 in the depth,
1.4 in its own length. Gill-rakers 7 -f- 12.

94

MEMOIRS OF THE CARNEGIE MUSEUM.

51. Odontostilbe microcephala Eigenmann.
Udontostilbe microcephalus Eigenmann, Proc. U. S. Nat. IMus., Vol. XXXIII, 1907,
p. 10.

Range : Paraguay and Upper Parana basins.
11086, 1. U. :M., type, 46 mm. 11086, 1. U. IM., paratype, 45 mm. Rio Pilco-

mayo, Bolivia. Exchange with British Museum.
6854a-e, C. M., five, largest about 80 mm. (the caudal is broken), the longest

on record for the genus. Rio Tiete at Salto Avanhandava below the falls.

Sept. 15, 1908. Haseman.
6855a-p, C. M., sixteen, largest 33 mm. Rio Tiete, Salto Avanhandava

above the falls. Sept. 14, 1908. Haseman.
6856a, C. M., one, 38 mm. Asuncion. March 28, 1909. Haseman.
Readily distinguished from the other members of the genus by the teeth, by
the elongate form and prominent caudal spot.

Head 4-4.6; depth 3^; D. usually 11, rarely 10; A. ^i^, ^-, ^, ^f-; scales

Fig. 35. Odontostilbe microcephala Eigenmann. a, premaxillary; 6, maxillary; 6' left maxillary of
another individual; c, mandible. (All figures greatly enlarged).

or 5; eye 2.5-3 in the head, equal to or a little greater than the
interorbital, .6-.9 (in largest) in the snout; depth of the caudal peduncle 2.33-3
in the depth, .4 of its own length.

Elongate; dorsal and ventral profiles similar; preventral area flat, with a
regular median series of fifteen scales; predorsal area rounded, with a median
series of eleven scales. Occipital process one-fifth to one-eighth in the distance to
the dorsal; frontal fontanel about 2.5 in the parietal; second suborbital and the

EIGENMANN: the CHEIRODONTINiE. 95

postorbitals leaving a very narrow naked area between them and the upper limb
of the preopercle. Snout pointed, maxillary scarcely reaching to origin of eye,
its length about .6 or .7 that of the eye; usually two maxillary teeth, rarely one
or three; premaxillary and mandibular teeth similar, their margins rounded, the
median cusp slightly the larger, five, very rarely six, teeth in the premaxillary;
mandibular teeth eight to ten; the premaxillary teeth slightly directed backward,
the teeth in the largest specimen (6854a) are much broader, more symmetrical, and
the differences between the points are very slight, the smallest specimen, from the
same locality has fewer points and the median point is distinctly- more prominent.
Gill rakers 7 + 10.

Origin of dorsal a little nearer end of adipose than to tip of snout; highest
dorsal ray equals length of head; adipose fin well-developed; origin of anal below
tip or middle of last dorsal ray, the fin emarginate, its base equalling length of head
or a little more; tip of ventrals to the anal or to the third scale in front of it; origin
of ventrals under, or slightly in advance of, the origin of the dorsal; the pectorals
to the ventrals, or to the third scale in front of them.

Scales thin, regularly imbricate; lateral line but little decurved; caudal naked;
anal with a few scales forming a sheath in front.

A silvery lateral band ending in a large, oval spot on the caudal peduncle,
which extends a little upon the middle caudal rays and sometimes entirely across
the end of the peduncle.

52. Odontostilbe pulchra (GiU.) (Plate XVII, fig. 1.)
Poedlurichthys pulcher Gill, Ann. Lye. Nat. Hist., Vol. VI, 1858, p. 59 (Trinidad).
Cheirodon (Odontostilbe) pulcher Liitken, Overs. Dan. Selsk., 1874, p. 236.
Odontostilbe pulcher Eigenmann & Eigenmann, Proc. U. S. Nat. Mus., Vol. XIV,

1891, p. 54; Eigenmann, Reports Princeton Univ. Exped. Patagonia, Vol. Ill,

1910, p. 429.
Cheirodon pulcher Ulrey, Ann. N. Y. Acad. Sci., Vol. VIII, 1895, p. 290.
Chirodon pulcher Regan, Proc. Zool. Soc. London, 1906, p. 385 (Trinidad).

Range: Trinidad.

As far as known this species is confined to the Island of Trinidad. I have seen
no specimens.

The following description is compiled from Regan's account:

Head 4.5-4.66; depth 2.5-2.75; D. 11; A. 23-25; scales 5.5-32 to 34-3.5-4.5,
4.5-5.5 between lateral Une and anal. Snout 5 in the head, eye 2.5, interor-
bital 2.25.

96 MEMOIRS OF THE CARNEGIE MUSEUM.

Maxillary extending to the vertical from the anterior margin of eye. Origin
of dorsal equidistant from snout and base of caudal, its height greater than head.

Pectorals extending to ventrals, origin of ventrals in advance of dorsal, extend-
ing nearly to the anal. Caudal i^edunclc as long as deep.

Olivaceous, sides silvery, or a silvery longitudinal stripe from operculum to
base of caudal; an indistinct dark humeral spot; a blackish spot at the base of
caudal, ending posteriorly in a point and margined with yellow above and below;
dorsal and anal pink.

53. Odontostilbe paraguayensis Eigenmann & Kennedy. (Plate XVI, fig. 2;

plate XVII, fig. 3.)

Odontostilbe paraguayensis Eigenmann & Kennedy, Proc. Acad. Sci. Phila., 1903,

p. 512 (Asuncion; Arroj'-o Trementina); Eigenmann, Ann. Carnegie Museum,

Vol. IV, 1907, p. 125 (Corumba); Reports Princeton Univ. Patagonia, Vol.
Ill, 1910, p. 429.

Range : Paraguay basin .

9988, I. U. M., type, 40 mm. Asuncion. J. D. Anisits.

10111, I. U. M., three, 40 mm. Arroyo Trementina. J. D. Anisits.

10178, I. U. M., five, Corumba. J. D. Anisits.

6853a-m, C. M., fourteen, 22-39 mm. Asuncion, March 29, 1909. J. D.
Haseman.

This is the deepest of the species of Odontostilbe, greatly differing from the type,
0. fugitiva, in depth.

Head 3.75-4.5; depth adult female 2.6, adult male 3; D. 11; A. 21-24;
scales 6-32 to 35-4; eye 2.66-3 in head, about equal to interorbital; depth of
caudal peduncle 2.66-3.25 in the greatest depth.

Compressed; dorsal and ventral profiles about equally curved, the depth in-
creasing rapidly to the origin of dorsal and tapering to the slender caudal peduncle;
preventral area flat, with well marked lateral angles, with a perfect median series
of eleven to thirteen scales, or but one scale disarranged; predorsal area keeled
with about nine scales; occipital process pointed, reaching about one-fourth to the
dorsal; skull smooth, convex, frontal fontanel a nearly equilateral triangle about
one-third as long as the parietal fontanel without the groove; third suborbital
leaving naked onlj' a small wedge of the cheek behind its upper angle; postorbitals
very thin, leaving this area practically naked; mouth small, maxillary reaching
to, or not quite reaching, the vertical from the anterior margin of the eye, about
half as long as eye; premaxillary with five or six sub-ovate teeth, each with a

eigenmann: the cheirodontin^. 97

prominent median cusp and four, rarely five, more or less graduate cusps on each
side, the two edges of the teeth not quite symmetric; maxillary with two or three
broad teeth; mandible with eight graduate teeth, the anterior ones very wide at
the tip, contracted at the base, with a prominent median point and three or four
slightty graduate points on each side of it, the tips of the lateral points forming a
slight curve bej'ond which the median point projects somewhat, the median cusp
at least t^nce as wide as the two cusps on either side of it; the edges of the teeth
overlapping more and more toward the sides of the jaw. Gill-rakers 6 + 10.

Origin of dorsal about equidistant from tip of snout and tip of adipose, its
height equal to the length of the head; adipose well-developed; caudal lobe a little
longer than head; origin of anal about under vertical from tip of last dorsal ray,
its margin nearly straight from the ninth raj', its base about equal to the head.
Origin of ventrals about equidistant from snout, with the origin of the dorsal just
reaching anal, or falling short of it bj^ one scale ; pectorals not quite reaching ventrals.

Lateral line nearly straight; scales everj'where regularly imbricate; caudal
naked; anal with a few scales at the base of the anterior lobe; about six feeble
interhsemals ; caudal in male without hooks or special scales.

A silvery lateral band; a conspicuous caudal spot, not continued to the middle
of the central caudal rays; anterior margin of dorsal membrane dark.

54. Odontostilbe madeirae Fowler.
Odontostilbe madeirce Fowler, Proc. Acad. Nat. Sci. Phila., 1913, p. 527 (tributary

of the Rio Madeira near Porto Velho).

Fig. 36. Odontostilbe madeirce Fowler. (After Fowler, Proc. Acad. Nat. Sci. Phila., 1913, p. 527.)

Range: Madeira basin.

This species is known from the types only. It may be sj^nonymous with 0.
'Paraguay ensis.

98 MEMOIRS OF THE CARNEGIE MUSEUM.

Head 3.6; depth 2-7/8; D. 12; A. 23; scales 6-37-4; 11 predorsal scales; eye
3-1/8 in the head, maxillary 3-1/8, interorbital 3; height of dorsal 1; height of
anal 1.4; depth of caudal peduncle 2.5; pectoral 1.25; ventral 1.4.

Compressed, elongately ovoid; mouth short, jaws thin; lips thin; maxillaiy
reaching the eye; teeth broad, with seven denticles, of which the median largest;
maxillary with two similar teeth; suborbitals entirely covering cheek.

Dorsal inserted nearly midway between tip of snout and end of adipose; origin
of anal close behind vertical from end of dorsal, lowest edge of anal emarginate;
ventrals inserted slightly behind origin of dorsal, extending to anal.

Margin of scales of back dusted, a patch of dusky dots above base of anal.
Base of caudal with a large rounded spot about as large as eye. A dark line con-
current with vertebral axis from behind shoulder to caudal.

55. Odontostilbe melandeta Eigenmaim.
OdontostUbe mdandelus Eigenmann, Mem. Carnegie Mus., Vol. V, 1912, p. 312,

Plate XLIV, fig. 3 (British Guiana, probably Rockstone on the Essequibo

river).

Range: British Guiana.

1878, C. ]\I., type, 27 mm.; 12160, I. U. M., two, paratypes, 27 and 35 mm.
British Guiana. Eigenmann.

Known only from the types. This species is more cylindrical, its scales firmer,
its teeth smaller. It is quite possible that it represents the type of a distinct genus.

Head 3.75; depth 3.6; D. 10; A. 21; scales 4-34 or 35-3. Eye 2.5-2.7 in
the head, interorbital but little narrower than the eye.

Minute, compressed, head bluntish, mouth terminal; a median series of ten
scales in front of the dorsal. Maxillary very slender, reaching to below the eye;
maxillary-premaxillary border as long as the eye; ten to fourteen teeth on the pre-
maxillary, four to seven on the maxillary.

Scales ver}^ regularly imbricate, with concentric, but without longitudinal
strise; lateral line complete, scarcely decurved; anal naked; base of caudal with a
few scales.

GiUs well-developed; anal deeply emarginate; pectorals not quite reaching
ventrals, ventrals not reaching anal. T

No chromatophores on the sides; scales of the back with marginal series of
chromatophores; a series of black specks along the base of anal; caudal peduncle
mai;gined with black.

EIGENMANN: the CHEIRODONXINiE. 99

APPENDIX.

Since the foregoing pages were sent to press the author has discovered among
the material collected by Mr. Henn during his explorations in Ecuador an addi-
tional species, a description of which follows :

56. Megalamphodus ecuadorensis sp. nov.

13628, I. U. M. Type, about 28 mm., 20.5 mm. to base of caudal. Naranjito,
Rio Chan Chan, Ecuador. Henn.

Of this species, the only one of the subfamily found on the Pacific slope of the
northern half of South America, I have but a single, poorly preserved specimen.
Head 3.4; depth about 3; D. ?; A. 23; Scales ?; eye 3 in the head, a Uttle greater than
the interorbital.

Compressed; dorsal and ventral outlines equally curved. Fontanels very large,
the frontal fontanel entirely separating the frontal bones; third suborbital Graving /ea>Ancj ti-ii^rA-
eivuir^only a narrow naked p^ge behind it. Mouth large, the maxillary-premaxillary
border longer than the eye. Seven or eight premaxillary teeth, which are slightly
graduate; maxillary with two small teeth (on one side at least); mandible with
about fifteen teeth, of which the first four or five are nearly equal in size, larger
than the premaxillary teeth, the rest rapidly diminishing in size. Origin of the
dorsal a little behind the middle, 12 mm. from the tip of the snout, 10.5 mm. from
the base of the middle caudal rays; origin of anal on vertical from origin of dorsal;
height of dorsal very nearly equal to length of head; pectorals extending beyond
the base of ventrals, ventrals beyond origin of the anal. The scales are BmaJL A
well-defined, vertical humeral spot; margin of anal dark. mostJ'iMt Bfv^rj,^

Mimagoniates Regan, Ann. & Mag. Nat. Hist., (7), XX, 1907, p. 402.

This genus is related to Prionobrama Init lacks maxillary teeth and the anal
is but slightly emarginatc. The original description by Regan follows.

"Body strongly elongate, compressed; abdomen keeled, but not strongly
compressed to an edge. Mouth small; teeth tricuspid, in a single series; no maxil-
lary teeth: palate toothless. Nostrils close together. Gill-mcmbranos not united,
free from the isthmus. Scales cycloid, of moderate size; lateral line incomplete.
Dorsal fin short, posterior in position; adipose fin present; anal fin elongate.

"Intermediate between Chirodon, Girard, and Leptagoniates, Blgr."

Mimagoniates Barberi Regan.

"Depth of body 3-3.66 in the length, length of head 4-4.4. Snout much

shorter than eye, the diameter of which is 2.5-2.75 in the length of the head and a

little less than the interorbital width. Cleft of mouth nearly vertical; maxillary

not extending to below the eye. 42-45 scales in a longitudinal series; lateral line

xxi

XXU ADDENDA AND CORRIGENDA CHEIRONDONTIN^.

on 4-8 scales only. Dorsal 10; origin equidistant from gill-opening and base of
caudal, above the anterior part of the anal. Anal 34-38; origin equidistant from
anterior part of eye and base of caudal; anterior rays the longest, about .6 the
length of head; free edge straight or slightly concave. Pectoral extending to or a
little beyond the base of ventral. Caudal forked. A lateral band (blackish in
preserved specimens) from the lower part of eye to the lower lobe of caudal. An
oblique dark stripe on the dorsal; anal with a dark margin.

"Habitat, Arroyo Yacd, Estacion Cabellero, Paraguay.

"Several specimens, the largest 40 mm. in total length, collected by Dr. A.
Barbero."

Chirodon arnoldi Boulenger, Ann. and Mag. Nat. Hist. (6), Chirodon arnoldi
Boulenger, Ann. and Mag. Nat. Hist. (8), IV, p. 497.

This species described as a Cheirodon is probably a Hemigrammus. If it is a
Cheirodon and if it comes from the northern part of the Isthmus of Tehuantepec,
it extends the known range of the genus Cheirodon northward for more than ten
degrees latitude.

Head 4; depth 3. D. II. 9: A. III. 19; scales 32, 4 or 5 with pores, 11 scales in a
transverse series.

Strongly compressed, snout shorter than eye, eye 2.66 in head, equals inter-
orbital; maxillary not reaching anterior border of eye; lower jaw scarcely projecting.
Origin of dorsal just behind base of ventrals, equidistant from snout and caudal
longest ray of dorsal as long as head.

Yellowish above, finely speckled with black, silvery white beneath; a large
round black spot on caudal peduncle, extending on base of middle rays of caudal;
dorsal, ventrals, and caudal tinged with orange.

Length 33 mm. Said to have been imported by the Aquariest Arnold of Ham-
burg from Puerto Mexico, on the north coast of the Isthmus of Tehuantepec.

Memoirs Carnegie Museum, Vol. Vll,

Plate II.

A A / A A A / ,y / V V<,

Fig. 1. (irunditlus bogotcnsi.s (Humboldt). 0084, C. M., 7G mm. \'icinity of Bogota.
Fig. 2. Aphyocharaz paraguayensis Eigexmann. Type. 6096, C. M., 25 mm. Caccrcs.

Memoirs Carnegie Museum, Vol. VI

Plate III.

-■■■^

Fig. 1. S/ii'iilhrnihiiliis jHiplllifcni.y Eir.KNMWN. TyiK'. 3882, C. M., II iiiiii. Alto da Scrra.

Fig. 2. Siii)itlicr<ibi)liis papillifcnts Ki(iKNM.\NN. 3883a, C. M.

Fi(i. 3. Spintherobolus pnpillifcrus Ei(iK\M.\Ni\. 3883a, C. M.

Fk;. 4. Siiinthrrobohif: pdpillifcrm Ei(iKNM.\NN. 3883a, C. M.

Fi(i. 5. Aphijocharax ratlihuiii Kigknmann. (Type of A. slramincKs Kiy,('iiinann.) 1()()3(), I. l". M.

of caudaL Arroyo Trcmontina.

Fig. G. Aphijocharax anisilsi lOKiiON.MAN.N iV- Kkwkdv. Type. 10028, I. l'. M., 41 iiiiii. Asuncion.

2.") mm. to ha.sc

^

&-

o

r' -r o

tc^

r^

■? = s o

X K = cT

5 ^"'S

>^

:<:Sg^

Fd

«

. .d g

=a

g S3_-2

z 2 c

a X =0

t: .a fc s:

5 2 -o .0

-« £:■?: = =

— (N CC -^ 'C

c c c d o

U< b b (-1 (ih

Memoirs Carnegie Museum, Vol. VII.

Plate V.

EWMTA Fi(!. 1. Phrttjaacninir- cffYrifini.FirT'iM \ r;M Type. 5354, C. M., 41 mm. Mamgru.

Fig. 2. Parecbasis cijcloiepis Eigexmann. Type. 5495, C. M., 74 mm. San Antouio de Rio Madeira.

Memoirs Carnegie Museum, Vol. VII

Plate VI.

V,' V / V V Y L )-- ^ '

tSM:h

Vir,. 1. Leptobrycon jdliainuKr Imcenmann. Type.\ 20952, M. C Z., 2!) nun. to base of caudal. Jatuarana.
Fig. 2. MacropKobri/con unujiKiijdiin' EiCENMAyiN. T>]i('. 6895, C. I\I., 4(i mm. Cacoquy.

Memoirs Carnegie Museum, Vol. VII

Plate VIII.

Fig. 1. MriitildiiijthdilNs nn'rniplcnisEM.KSMASS. Tyiu'. (illOO.C. .M.,:5() nun. I.a^dailo I'orto, Basin Rio S. Francisco.
Fig. 2. MicroKchimobrijain (juaporends Eigenm.\nn. Typo. G910, C M., alxmt '.il mm. Maciel.

Memoirs Carnegie Museum, Vol. VII.

Plate IX.

Fifi. 1. Oligobrycon microstomu-s EiGE:^M\>is. Typo. (5898, C M., 39 mm. Jacarcliy, Rio S. Francisco
Fig. 2. Apkyocheirodon hemigraminus Eigenmann. Type. 6802, C. M., 45 mm. Jaoiuara.

Memoirs Carnegie Museum, Vol. Vll

Plate X.

Fui. 1. CompfsuraheterurnE\v,ENM\>i\. 'Jyiic, o". 1)808, C IM., 36 nun. (^iciiuadas Hio Itapicii/ru. ^^'^■^M
Fig. 2. Mixobri/con ribeiroi Eigknm.vnn. Type. 10229, I. V. IM., 35 mm. to base of caudal. Puerto Max, Parajiuay.

Memoirs Carnegie Museum, Vol. VII.

Plate XI.

Cluinxlini (iiiiHV McAtek. 4301, I. U. A[.. II nun. S. .\nicric;i. lv\act locality unkudwii.
Chiinxhiii iiiinihtihw EitiKXM.VNN. Type. 6841, V. M., 38 mill. Caniiio.';. on K. l'araliyi)a.

Memoirs Carnegie Museum, Vol. VII.

Plate XII.

Fig. 1. Cliciroildu i uterruj)! us ,]K\Yfis, 9. (1818, C M., 44 mm. Cachoi-ira, H. Jaculiy, R. CJraiuIr do iSul.
Fig. 2. Chcirodon nuloinelas Eigenmann. Type, 9 • 0812, C. M., 35 mm. Miguel Calmone.

Memoirs Carnegie Museum, Vol. VII,

Plate XIII.

\ -~ ^ i'^, A A A AAA
;\i Y V V V

■/-A K k -k I
■ / \/ f/ \/ \j

A A A A A A A A V^

^ •.J:..U.sj\^

I'lu. 1. C7tt;;'o(/c//i w(a(/(.'/nt EiGENMANN. Type. (JS17, C. M., 32 iniu. San Joaquin.
Fig. 2. Cheirodon piaba Lutken, <f. 6822, C. M., 40 mm. Corumbd.

Memoirs Carnegie Museum, Vol. VII.

Plate XIV.

Fig. 1.
Fig. 2.

Chcirudun micnxUin Eigenm.\nn.
Cheirvdon slenodon Eigenmann.

Type, 9 . tiS.50, C. :M., 42 mm. Cacercs.
Type. 6848, C. M., 33 mm. Bebedouro.

Memoirs Carnegie Museum, Vol, VII,

Plate XV.

V V V V V
S h A, A, A. ^

yVVfvVvVvVVV

V V Y y V V V ^ V V' V V \ y / K ViW^

Fig. 1. Ildlrslhc.s pequira (StciiKlachiKM-). 0857, C. M., 44 mm. \"illa Hay.s.
Fig. 2. Holcsthes heterodonEiCEJ^MANN. Paratype. 6876, C. M., about 40 mm.

Jacuara.

Memoirs Carnegie Museum, Vol. VII

Plate XVI.

Fic. 1. OilniilDstilbc ha.stala Kic.KSMA^is. 5306. ('. M.. :>l) nun. Kio 'I'niandu, C\>loMilii;i.
Fig. 2. (hlonlodHbc pariKjiimjeii.sis Ek;en.m.\xn & Kk.\.\kdv. 6853, C M., 36 nun. Asuncion.

Memoirs Carnegie Museum, Voi,. VII

Plate XVII.

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. (5.

tyiniianum.)

Odontostilbe pulchra (Gill). (After Rogan.)

Cheirodon insignis Steind.\chner. (After Steindaehner.)

Odontostilbe pnraguai/ensis Eigenmann & Kennedy. 1017S, I. U. JM.

Cheirodon pisciculus Girard. (After Girard.)

Cheirodon piaba Lutken. (After Liitken.)

Cheirodon pi(d)a LI'tkex. 10121,1. U. I\I. (Greatly enlarged to show the pseudo-